PubAnnotation

Id	Subject	Object	Predicate	Lexical cue
T1	2430-2599	Epistemic_statement	denotes	Interestingly, the Maori had a higher death rate (43.3/1000) than Europeans (7.6/1000), a finding that suggests prior exposure to influenza may have minimized mortality.
T2	2600-2754	Epistemic_statement	denotes	Jeffrey Taubenberger has sequenced the HA, NA, NS, M, and NP genes of the 1918 Spanish influenza virus and found that it is closely related to swine H1N1.
T3	2755-2847	Epistemic_statement	denotes	Unfortunately, the molecular basis of the high pathogenicity of this virus is still unknown.
T4	2848-3079	Epistemic_statement	denotes	Likewise, it is unclear if the virus, the hemagglutinin and neuraminidase genes of which derived 1977-present No from an avian influenza virus, directly infected man and then infected pigs or if pigs served as an intermediate host.
T5	3851-4050	Epistemic_statement	denotes	Acquisition of avian influenza genes by swine influenza viruses has been documented in H1N1 isolates in Europe, H4N6 in Canada, and H9N2 in China, although these latter two instances were transitory.
T6	4051-4252	Epistemic_statement	denotes	In the United States, H3N2 viruses became a problem in pigs in 1998 when the infection was associated with respiratory signs, high fever (104-107 • F), high morbidity (100%), and high risk of abortion.
T7	4339-4560	Epistemic_statement	denotes	Interestingly, analysis of three of the porcine H3N2 viruses revealed that the virus has undergone triple reassortment and had acquired human PB1, HA, and NA genes, porcine NP, M, and NS genes, and avian PA and PB2 genes.
T8	4561-4674	Epistemic_statement	denotes	There is growing evidence, too, that H1N1 swine influenza A viruses are acquiring avian polymerase genes as well.
T9	4675-4903	Epistemic_statement	denotes	Although pigs appear to be an important reservoir and mixing pot for potential human influenza viruses, the chicken H5N1 and H9N2 viruses that have recently emerged in Asia suggest chickens may also be an important intermediary.
T10	5444-5669	Epistemic_statement	denotes	Additional studies of the local chicken market demonstrated that when H5N1 virus infected a chicken it resulted in its death, while chickens co-infected with H9N2 viruses were protected from illness but efficiently shed H5N1.
T11	5670-5869	Epistemic_statement	denotes	The H5N1 virus still appears to be a problem with re-emergence of a different H5N1 virus in 2001; fortunately an outbreak of human infections was prevented by the massive slaughter of chickens again.
T12	6268-6450	Epistemic_statement	denotes	Upon further investigation of these H5N1 outbreaks in chickens and humans, it became clear that quail might play a significant role in interspecies transmission of influenza viruses.
T13	6451-6606	Epistemic_statement	denotes	It appears that quail acquire infection from fecal sources and then replicate virus in their respiratory tract with evidence of tracheal shedding of virus.
T14	6607-6722	Epistemic_statement	denotes	The outbreaks in chickens were associated with the reintroduction of H6N1 and H9N2-infected quail into the markets.
T15	6723-6871	Epistemic_statement	denotes	To address the concerns that quail are intermediates in the transmission of influenza, quail have been banned from all poultry markets in Hong Kong.
T16	7237-7396	Epistemic_statement	denotes	Since the H5N1 virus has caused severe disease in humans already and is a potential pandemic threat, several researchers are looking for its virulence factors.
T17	7693-7851	Epistemic_statement	denotes	Several studies subsequently documented that the NS1 protein of the H5N1 was an antagonist of the antiviral activity of several cytokines (Seo et al., 2002) .
T18	9019-9079	Epistemic_statement	denotes	Unfortunately, powerful technique brings several challenges.
T19	9080-9346	Epistemic_statement	denotes	Since it is so easy to make reassortant viruses, it could be possible to create viruses with several pathogenic genes or viruses that are highly resistant to antivirals resulting in highly transmissible and lethal agents that could be used as agents of bioterrorism.
T20	9347-9487	Epistemic_statement	denotes	In this regard, dangerous constructs need to be contained within BSL3+ level facilities, limiting the number of centers that can study them.
T21	9488-9705	Epistemic_statement	denotes	To prepare for the future, with the current risks of bioterrorism and pandemic influenza, it is essential that surveillance, using global WHO human and animal networks, and yet to be developed biosensors, be expanded.
T22	9706-9907	Epistemic_statement	denotes	Additionally, vaccines and their production need to be studied since it currently takes 6 months to prepare a new vaccine and there may not be a mild warning wave of infection before the next pandemic.
T23	9908-9995	Epistemic_statement	denotes	Lastly, antivirals need to be stockpiled and new antiviral agents need to be developed.
T24	10702-10822	Epistemic_statement	denotes	Although most infections have been documented in children, up to 20% of infections occur in patients over the age of 60.
T25	10823-10983	Epistemic_statement	denotes	Preliminary data suggests that hMPV may be responsible for approximately 7-8% of viral respiratory tract illnesses (RTI) in children and 2-3% of RTIs in adults.
T26	11766-11901	Epistemic_statement	denotes	Sequencing of the N, P, M, F, M2, SH, G, and L genes indicates that hMPV is most closely related to APV (van den Hoogen et al., 2002) .
T27	12041-12157	Epistemic_statement	denotes	There appear to be two genetic and serotypic clusters of hMPV with two subclusters of each cluster (A1, A2, B1, B2).
T28	12158-12364	Epistemic_statement	denotes	(Guy Boivin, Laval University, Québec, Canada) A new paramyxovirus, the human metapneumovirus (hMPV), has been recently isolated from Dutch children with respiratory symptoms (van den Hoogen et al., 2001) .
T29	12365-12484	Epistemic_statement	denotes	However, the prevalence, clinical presentation, and severity of hMPV infections in children have not been well studied.
T30	13571-13767	Epistemic_statement	denotes	hMPV was associated with bronchiolitis in 66.7%, otitis media in 50%, and pneumonia in 16.7% of infected children; no hMPV children were sick enough to require admission to an intensive care unit.
T31	14025-14217	Epistemic_statement	denotes	Dr. Boivin also discussed an outbreak investigation in which there appears to be a nosocomial outbreak of hMPV in a nursing home, giving further information about the impact of this new virus.
T32	14377-14531	Epistemic_statement	denotes	(Robert Couch, Baylor College of Medicine, Houston, TX) Multiple respiratory viruses can be detected sometimes in patients with respiratory tract illness.
T33	14705-14782	Epistemic_statement	denotes	The frequency of dual infection appears to be higher in children than adults.
T34	14783-14868	Epistemic_statement	denotes	The types of diagnostic techniques utilized greatly impacts the detection of viruses.
T35	15801-15871	Epistemic_statement	denotes	The impact of dual infections on disease course has also been studied.
T36	16352-16523	Epistemic_statement	denotes	The exact mechanism for this reduction of viral shedding and symptom severity is not known but transient immunity from the previous infection may contribute to the effect.
T37	17216-17366	Epistemic_statement	denotes	Although not well controlled for in these studies, the timing of infection and the type of viruses likely impact the duration and severity of illness.
T38	17367-17644	Epistemic_statement	denotes	Available information is insufficient for firm conclusions on the illness consequences of dual respiratory viral infections, and future studies should be address the relationships between illness severity and etiology, time course, and quantitative virology of dual infections.
T39	17650-17893	Epistemic_statement	denotes	Respiratory pathogens in the first year of life: a birth cohort study using PCR (Sebastian Johnston, Imperial College London, UK) Numerous studies have documented an association between asthma exacerbations and respiratory viral illness (RVI).
T40	18036-18169	Epistemic_statement	denotes	Several recent studies have expanded on our understanding of the epidemiology of RVIs and their relationship to asthma exacerbations.
T41	19319-19663	Epistemic_statement	denotes	Patients with hRV infections alone were hospitalized earlier in an illness episode (1.8 days versus 3.1 days, P = 0.001) and had a higher likelihood of having a clinical severity score on admission above the 50th percentile (OR 4.9, P = 0.022) after controlling for age, gender, birth weight, presence of fever, and day of disease on admission.
T42	21061-21354	Epistemic_statement	denotes	Among those with URI, 84% had picornaviruses, 11% had RSV, and 5% had dual infections; non-wheezing LRI was associated with picornavirus detection in 74%, RSV in 23%, and dual infection in 3%; wheezing LRI was associated with picornavirus in 70% of cases, RSV in 22%, and dual infection in 8%.
T43	21423-21723	Epistemic_statement	denotes	Although RSV is perhaps more likely to be associated with severe lower respiratory tract illness, these data indicate that rhinoviruses are major respiratory pathogens during the first year of life and cause about three times as many LRIs in the first year of life as RSV in non-hospitalized infants.
T44	21724-21801	Epistemic_statement	denotes	The specific picornavirus that cause these illnesses remain to be identified.
T45	22993-23288	Epistemic_statement	denotes	Among the most prevalent serotypes associated with human respiratory disease, adenovirus type 7 (Ad7) is a frequent cause of severe clinical presentations in children and young adults, in whom it causes epidemics of acute febrile respiratory illness among military recruits (Ryan et al., 2002) .
T46	23289-23454	Epistemic_statement	denotes	Extrapulmonary manifestations, rare fatalities, and residual lung damage are observed in association with Ad7 infection (Becroft, 1967; Steen-Johnsen et al., 1969) .
T47	23455-23628	Epistemic_statement	denotes	Affected patients surviving severe disease may have chronic sequelae in the form of bronchiectasis, bronchiolitis obliterans and hyperlucent lung (Murtagh and Kajon, 1997) .
T48	23966-24146	Epistemic_statement	denotes	The molecular bases of these substitutions of one genome type for another, called genome type "shifts", and the selective forces driving adenovirus evolution in nature are unknown.
T49	24147-24236	Epistemic_statement	denotes	Moreover, the impact of genetic variability on adenovirus virulence is poorly understood.
T50	24551-24876	Epistemic_statement	denotes	Ad7b is still the most prevalent genome type isolated in Europe and North America and Ad7h is still recovered from the nasopharyngeal secretions of children hospitalized for ARI in the South America, observations suggesting an adaptive advantage of their array of genes over the preceding prevalent genome type in the region.
T51	24877-25190	Epistemic_statement	denotes	Interestingly, Ad7h has been recently detected in the United States and Japan in association with respiratory illness and in Brazil in association with acute conjunctivitis, findings that suggest a recent introduction and dissemination of this virus from previously geographically restricted areas of circulation.
T52	25191-25407	Epistemic_statement	denotes	Ad7d 2 , originally reported to circulate in China and later on in Japan and Israel, has been identified in recent outbreaks of ARI in the United States affecting children and military trainees Gerber et al., 2001) .
T53	25633-25743	Epistemic_statement	denotes	These findings suggest that genome type shifts are not strongly determined by selection of antigenic variants.
T54	26113-26340	Epistemic_statement	denotes	However, the implications of genetic variation for human disease are still unclear and will remain elusive until Ad7 genome types are characterized phenotypically and a correlation between genotype and phenotype is established.
T55	26630-26784	Epistemic_statement	denotes	Reverse genetics has been used to create viruses with an influenza A/WSN background, that contain genes from the 1918 strain or more contemporary strains.
T56	26785-26973	Epistemic_statement	denotes	In a recent experiment, conducted in a BSL4 laboratory, three viruses were created: a wild-type WSN virus, a WSN virus with 1918 HA and NA genes, and a WSN virus with 2001 HA and NA genes.
T57	27906-28017	Epistemic_statement	denotes	Such findings indicate that HA and NA of the 1918 virus are linked in part to its virulence in mammalian hosts.
T58	28018-28099	Epistemic_statement	denotes	Protection against the 1918 virus could be achieved by antivirals and antibodies.
T59	28481-28705	Epistemic_statement	denotes	The concept of original antigenic sin, in which humans exposed or vaccinated to influenza will produce higher antibodies against the first virus they were exposed to than against subsequent viruses, may explain this finding.
T60	28706-28852	Epistemic_statement	denotes	In turn, this could partly explain why older patients may have been relatively protected relative to younger individuals during the 1918 pandemic.
T61	28853-28994	Epistemic_statement	denotes	Another question that has recently been answered, although the significance of it is still under investigation, is how the virus is packaged.
T62	29125-29223	Epistemic_statement	denotes	Several studies were then conducted to determine if segment incorporation was random or selective.
T63	29863-29998	Epistemic_statement	denotes	This suggests that, although the NCFBP is required, the coding region, in this case NA, is required for incorporation into new virions.
T64	29999-30149	Epistemic_statement	denotes	Additional studies documented that this virion incorporation signal (VIS), which frequently contained UAU coding regions, was unique for each segment.
T65	30266-30550	Epistemic_statement	denotes	Lastly, the packaging of segments within the virion was assessed through electron microscopy, which demonstrated that there is likely an interaction between base pairs on each of the segments that results in the segments aligning with one another in a fixed way (Fujii et al., 2003) .
T66	30551-30658	Epistemic_statement	denotes	These interactions require greater study as this is a potential target for drugs or vaccines of the future.
T67	30900-31080	Epistemic_statement	denotes	The main challenge in creating a potential live vaccine is to develop a virus that is both highly and stability attenuated while maintaining a satisfactory level of immunogenicity.
T68	31081-31293	Epistemic_statement	denotes	Reverse genetics have be used to achieve this goal by creating an array of potential mutations, fine tuning the level of attenuation, increasing the immunogenicity of the virus, and decreasing its reactogenicity.
T69	31526-31807	Epistemic_statement	denotes	Vaccine candidates for RSV (strain A2 of subgroup A) had previously been developed by conventional biological means, involving passage at suboptimal temperature ("cold passage" [cp]) followed by chemical mutagenesis and the identification of temperature sensitive (ts) derivatives.
T70	32036-32143	Epistemic_statement	denotes	However, it retained the ability to cause mild nasal congestion and thus would require further attenuation.
T71	32407-32577	Epistemic_statement	denotes	This list was expanded by finding that a number of RSV genes, including NS1, NS2, SH and M2-2, could be deleted to yield derivatives that proved to be attenuated in vivo.
T72	32578-32794	Epistemic_statement	denotes	This new knowledge was applied to reverse genetics to create two new viruses, 248/404/ SH and 248/404/1030/ SH, the second of which shows promise in early clinical trials and appears to be free of residual virulence.
T73	32971-33282	Epistemic_statement	denotes	Reverse genetics also can be used to increase gene stability to prevent reversion by incorporating multiple point mutations, by designing amino acid substitutions to involve at least two nucleotide changes compared to assignments yielding wild type or wild type-like phenotypes, and by employing gene deletions.
T74	33283-33468	Epistemic_statement	denotes	Further investigation suggests that moving the G and F genes to a more proximal location in the genome results in increased efficiency of G and F expression and enhanced immunogenicity.
T75	33658-33921	Epistemic_statement	denotes	It might also be possible to reduce the reactogenicity of an RSV vaccine using strategies developed from immunobiological studies: one example would be to ablate the secreted form of G, which has been implicated in preferential sensitization of Th2 T lymphocytes.
T76	34128-34206	Epistemic_statement	denotes	Reverse genetics has also been applied to hPIV3 to develop vaccine candidates.
T77	34207-34325	Epistemic_statement	denotes	A promising hPIV3 vaccine candidate, cp45, had previously been developed by the conventional approach of cold passage.
T78	35402-35502	Epistemic_statement	denotes	This chimeric virus retained the attenuation phenotype and represents a promising vaccine candidate.
T79	35748-35838	Epistemic_statement	denotes	This suggests that a vaccine based on the attenuated bPIV3 backbone should be very stable.
T80	35839-36041	Epistemic_statement	denotes	It also indicated that the introduction of individual bPIV3 genes into hPIV3 is an additional strategy for attenuation, one that is now being pursued with a version of hPIV3 containing the bPIV3 N gene.
T81	36259-36503	Epistemic_statement	denotes	Here, the strategy of "importing" mutations, in particular from RSV and hPIV3, has been particularly useful and has resulted in the development of a number of attenuating mutations that will serve as the basis for live hPIV1 and hPIV2 vaccines.
T82	36504-36634	Epistemic_statement	denotes	Finally, reverse genetics have been used to create attenuated, chimeric virus vectors to protect against multiple paramyxoviruses.
T83	37180-37391	Epistemic_statement	denotes	The availability of PIV vectors expressing RSV antigens offers a novel approach for the immunization or, alternatively, provides an efficient method of "boosting" an initial vaccination made by a live RSV virus.
T84	37392-37707	Epistemic_statement	denotes	It is anticipated that these methods will result in the development of live vaccines against RSV and hPIV3, which preferably would be given in the first weeks of life, and against hPIV1 and hPIV2, which cause disease somewhat later during the first year of life such that vaccination could begin at 6 months of age.
T85	37908-38123	Epistemic_statement	denotes	The current threat of bio-warfare, in addition to availability of anti-influenza drugs for prevention and treatment, makes the rapid identification of these pathogens essential to medical personnel and the military.
T86	38124-38216	Epistemic_statement	denotes	In the battlefield situation, ambient storage and transport of specimens would be desirable.
T87	39829-40082	Epistemic_statement	denotes	Since room temperature storage techniques are easier to accomplish in most locations and since PCR techniques are widely available to the military, the techniques used in this study should expand the ability to provide respiratory pathogen surveillance.
T88	40328-40412	Epistemic_statement	denotes	Unfortunately, the world does not appear to be prepared for a pandemic of influenza.
T89	40752-40875	Epistemic_statement	denotes	Guidelines for vaccines have been developed, but there is widespread concern that vaccine production will lag behind needs.
T90	41383-41517	Epistemic_statement	denotes	Although progress is being made, a pandemic may occur at any time and greater steps need to be taken to minimize its potential impact.
T91	41518-41943	Epistemic_statement	denotes	The United States Department of Health and Human Services has established the Interagency Pandemic Influenza Working Group, with input from the Centers for Disease Control, the Food and Drug Administration, the National Institutes of Health, the Department of Defense, the Office of the General Council, the Office of Planning and Evaluation, the Office of Emergency Preparedness, and the National Vaccine Advisory Committee.
T92	42220-42436	Epistemic_statement	denotes	Several actions have been proposed to strengthen national and global capabilities for virologic and disease surveillance with a view to increasing the likelihood of early detection of viruses with pandemic potential.
T93	44137-44286	Epistemic_statement	denotes	A web-based program, FluAid 2.0 (http://www2.cdc.gov/od/fluaid) has been developed which will help states estimate the potential impact of influenza.
T94	44287-44439	Epistemic_statement	denotes	The third, and perhaps largest objective of the Working Group, is to strengthen influenza-related public health practices, infrastructure, and research.
T95	44772-45028	Epistemic_statement	denotes	Research on influenza biology and epidemiology, animal surveillance, and vaccine and antiviral development has been and will continue to be supported by NIH through grants to academic researchers and through grants that support public-private partnerships.
T96	45029-45215	Epistemic_statement	denotes	Development of cell culture-based vaccines and the testing in humans of candidate pandemic vaccines made using reverse genetics or classical reassortment techniques should be encouraged.
T97	45957-46051	Epistemic_statement	denotes	Such policies will need to take into account liability protection and equitable global access.
T98	46362-46571	Epistemic_statement	denotes	It is essential that policy makers and the public understand the potential threat that influenza poses to mankind so that firm political and financial commitments are made to minimize the impact of a pandemic.
T99	46572-46894	Epistemic_statement	denotes	The best defense against an influenza pandemic is to strengthen the capacity to respond to seasonal epidemics of influenza through improved surveillance, increased vaccine use, enhanced vaccine production, and development of a more effective vaccine delivery infrastructure that could function effectively in an emergency.
T100	46895-47052	Epistemic_statement	denotes	Policy makers should take advantage of and integrate bioterrorism planning with pandemic influenza preparedness and develop flexible, science-based policies.
T101	47150-47269	Epistemic_statement	denotes	Despite the significant progress made in some countries, pandemic influenza planning in Europe is still in its infancy.
T102	48883-49066	Epistemic_statement	denotes	If a monovalent vaccine was used in combination with a potent adjuvant, the required antigen could be potentially reduced to 3.25 g and increase capacity to 12 million doses per week.
T103	49575-49695	Epistemic_statement	denotes	Likewise, there has yet to be a concerted effort to stockpile antiviral agents and supplies of these agents are limited.
T104	50096-50285	Epistemic_statement	denotes	Pandemic plans have been developed in 19 of the 20 European Influenza Surveillance Scheme participating countries, although implementation of the plans has been, for the most part, limited.
T105	50496-50612	Epistemic_statement	denotes	Australia has developed a 'Framework' for an influenza pandemic plan and has begun to implement its recommendations.
T106	50613-50888	Epistemic_statement	denotes	The Influenza Pandemic Planning Committee (IPPC) was chartered to develop a contingency plan and make recommendations for infrastructure and strategies required to minimize the mortality, morbidity, social disruption and economic losses associated with an influenza pandemic.
T107	50889-51173	Epistemic_statement	denotes	The work of the Committee and its recommendations were published as a comprehensive document which incorporated as an appendix the contingency plan for health care institutes prepared for the Victorian state plan: http://www.health.gov.au/pubhlth/strateg/communic/ tech/influenza.htm.
T108	51308-51577	Epistemic_statement	denotes	The major recommendations were the maintenance of an ongoing pandemic planning committee, further impact modeling, adoption of WHO 'alerts', improvement of interpandemic use of vaccine, development of an antiviral stockpile, and development of communication strategies.
T109	51578-51686	Epistemic_statement	denotes	A National Pandemic Action Committee (NIPAC) has recently been formed with the following terms of reference:
T110	51687-51719	Epistemic_statement	denotes	During the interpandemic period:
T111	51720-52162	Epistemic_statement	denotes	• Assisting the Government with development of national policies on vaccination strategies, surveillance and antiviral stockpiling; • Establishing working parties to progress policy issues from the Action Plan; • Collaborating with the States and Territories to prepare their plans; • Revising and promoting the Action Plan in consideration of the changing global agenda; • Regularly reporting progress to the Department of Health and Ageing.
T112	52499-52846	Epistemic_statement	denotes	However, whilst these steps have been taken and pandemic planning has been elevated within the bureaucracy, there has yet to be significant commitment of funds, there has been little regional involvement and, apart from representation through the WHO Collaborating Centre, Australia has not yet contributed greatly to global pandemic preparedness.
T113	53351-53629	Epistemic_statement	denotes	Susceptibility to pandemic influenza will depend on whether the virus is a re-emergent virus similar to one that has infected people in the past, for example influenza A (H2N2), or an entirely new virus like the avian influenza A (H5N1) virus that appeared in Hong Kong in 1997.
T114	53630-53868	Epistemic_statement	denotes	If it is an influenza A (H2N2)-like virus, people over the age of 35 years (approximately 40% of the world's population) are likely to have been immunologically primed by past infection and will require only one 'booster' dose of vaccine.
T115	53869-53973	Epistemic_statement	denotes	If the virus is entirely new, no one will have been primed and everyone will probably require two doses.
T116	53974-54236	Epistemic_statement	denotes	Moreover, because the clinical effectiveness and cost-effectiveness of vaccinating not only older adults but also younger adults and children is widely appreciated, health officials in many countries may choose to vaccinate most, if not all of their populations.
T117	54670-54773	Epistemic_statement	denotes	For this reason, companies make conservative estimates of how much vaccine they will produce each year.
T118	54774-54956	Epistemic_statement	denotes	When demand for vaccine increases suddenly, as it will when a pandemic threat appears, vaccine companies will probably lack the production capacity to respond adequately and quickly.
T119	54957-55138	Epistemic_statement	denotes	Because a pandemic vaccine will probably be monovalent rather than trivalent, it is theoretically possible that the number of doses that might be produced could increase three-fold.
T120	55139-55225	Epistemic_statement	denotes	Nonetheless, pandemic vaccine is still likely to be in short supply in most countries.
T121	55226-55385	Epistemic_statement	denotes	Prudent national health officials may choose to lock in a future supply of pandemic vaccine by negotiating a long-term forward contract with a vaccine company.
T122	55542-55719	Epistemic_statement	denotes	When a pandemic threat appears, within a period of a few months scores of countries will try to negotiate contracts for pandemic vaccine supply with a small number of companies.
T123	55788-55930	Epistemic_statement	denotes	Moreover, they are likely to be compromised by the 'nationalization' of vaccine production in countries that have influenza vaccine companies.
T124	55931-56034	Epistemic_statement	denotes	This is what political leaders in the United States did for Swine influenza vaccine production in 1976.
T125	56035-56179	Epistemic_statement	denotes	Canadian health officials remember this well, which is one reason why they signed their contract with their domestic influenza vaccine producer.
T126	56410-56472	Epistemic_statement	denotes	This new approach must address the following six major issues.
T127	56473-56578	Epistemic_statement	denotes	(1) When a pandemic threat appears, there will be delay in preparing seed strains for vaccine production.
T128	56579-56658	Epistemic_statement	denotes	This might be overcome by using reverse genetics to prepare these seed strains.
T129	56659-56761	Epistemic_statement	denotes	In principle, reverse genetics could be used to prepare high-growth variants for efficient production.
T130	56762-56973	Epistemic_statement	denotes	This may be essential if the pandemic virus is of avian origin because many of these viruses grow poorly (or not at all) in embryonated eggs, the culture system used for all current influenza vaccine production.
T131	56974-57218	Epistemic_statement	denotes	As long as issues regarding the worker safety and the intellectual property rights attached to reverse genetics can be sorted out beforehand, this promising technique could be the key factor for ensuring adequate production of pandemic vaccine.
T132	57219-57301	Epistemic_statement	denotes	(2) Whether the pandemic threat is due to a re-emergent (A/H2-like) or novel (e.g.
T133	57302-57438	Epistemic_statement	denotes	A/H5-like) virus will determine not only the kind of vaccine that should be produced but also whether one or two doses will be required.
T134	57550-57710	Epistemic_statement	denotes	Studies conducted many years ago indicated that whole cell vaccines were more immunogenic than split virus or subunit preparations of similar antigenic content.
T135	57711-57839	Epistemic_statement	denotes	Moreover, recent studies have shown that an adjuvanted vaccine will probably be needed for at least the first if not both doses.
T136	57840-57950	Epistemic_statement	denotes	These studies need to be extended in a larger series of clinical trials of candidate 'pandemic-like' vaccines.
T137	58174-58302	Epistemic_statement	denotes	In Western Europe, immunogenicity studies must be undertaken by vaccine companies each year in order to register their products.
T138	58501-58571	Epistemic_statement	denotes	For the next pandemic, such trade is likely to be much more extensive.
T139	58572-58815	Epistemic_statement	denotes	If pandemic vaccines are to be delivered quickly to the countries where they are needed most, a global protocol will be required that will allow the pandemic vaccine produced by any company to be registered for use in any country of the world.
T140	58816-58950	Epistemic_statement	denotes	The need for a protocol for the global registration of pandemic vaccines should be considered before the next pandemic threat appears.
T141	58951-59087	Epistemic_statement	denotes	(4) Countries will be better prepared for the next pandemic if they can increase their use of influenza vaccine in inter-pandemic years.
T142	59088-59243	Epistemic_statement	denotes	This was started by the Canadian province of Ontario in 2000, when it extended its recommendation for influenza vaccine to all people over 6 months in age.
T143	59326-59533	Epistemic_statement	denotes	Health officials can help prepare for the next pandemic by expanding their influenza vaccination recommendations and extending their programs for public reimbursement for vaccination in inter-pandemic years.
T144	59671-59844	Epistemic_statement	denotes	Although many vaccine companies are expanding their production facilities, it is still difficult for them to estimate future demand for inter-pandemic and pandemic vaccines.
T145	59982-60420	Epistemic_statement	denotes	One way to overcome uncertainty about future demand for influenza vaccines would be to: (a) obtain country-specific data on the number of doses of influenza vaccine distributed each year by each vaccine company and rapidly report the total number of doses distributed per 1000 population in all countries; and (b) obtain 5-year rolling forecasts of the demand for inter-pandemic and pandemic vaccine from health officials in each country.
T146	60421-60633	Epistemic_statement	denotes	The availability of such past and future information would challenge health officials to make more comprehensive plans for vaccination programs and help companies make more realistic plans for vaccine production.
T147	60634-60845	Epistemic_statement	denotes	(6) Political leaders in most vaccine-producing countries will probably prohibit the export of domestically produced pandemic vaccine to other countries until they are certain their national needs have been met.
T148	60846-61064	Epistemic_statement	denotes	As a result, countries that do not have vaccine companies, including many that currently use large amounts of vaccine in inter-pandemic years, may find it difficult or impossible to obtain supplies of pandemic vaccine.
T149	61411-61560	Epistemic_statement	denotes	Effective planning for pandemic influenza and the global vaccine supply will require the skills of experts in virology, epidemiology and vaccination.
T150	61561-61650	Epistemic_statement	denotes	Equally important, however, will be the skills of experts in politics, economics and law.
T151	61651-61727	Epistemic_statement	denotes	Coordinating their efforts at an international level will be very difficult.
T152	61901-61948	Epistemic_statement	denotes	How good are the rapid diagnostic tests really?
T153	61949-62509	Epistemic_statement	denotes	(Peter Wright, Vanderbilt University Medical Center, Nashville, TN and Ruth Karron, Johns Hopkins University, Baltimore, MD) Rapid diagnostic tests for respiratory viral illness has become an increasingly important tool because of the advent of effective antiviral agents that are maximally effective if started early in the course of the illness, the need to isolate patients who could pass their infection to other ill patients, and the need to differentiate between these viral illnesses and other respiratory tract pathogens, including bioterrorism agents.
T154	62510-62574	Epistemic_statement	denotes	However, currently available rapid testing has many limitations.
T155	62575-62952	Epistemic_statement	denotes	Areas of improvement that need to be addressed include the ability to test for all or most know agents, improved collection methods, improved integration of diagnosis with use of medications and clinical care, use of diagnostics for epidemiology and vaccine development, increased sensitivity in adults and immunocompromised patients, and improved ease and accuracy of testing.
T156	63029-63263	Epistemic_statement	denotes	There are significant limitations of these tests including sensitivities and specificities that are dependent on the quality of the sample collected, the timing of the illness, the intensity of the epidemic, and the population tested.
T157	63264-63437	Epistemic_statement	denotes	These assays have been developed to allow for sentinel surveillance, although their positive predictive values are limited at the beginning and end of epidemics (see below).
T158	63438-63614	Epistemic_statement	denotes	In addition, rapid testing helps to identify patients who may benefit from antiviral agents and to decrease the use of antibiotics and shorten the duration of hospitalizations.
T159	65071-65309	Epistemic_statement	denotes	Unfortunately, reported sensitivities and specificities of these various tests cannot be directly compared, since different 'gold standards', source populations, sample types (fresh versus frozen; nasal versus throat), and operators (i.e.
T160	65415-65723	Epistemic_statement	denotes	Use of a particular rapid diagnostic test for influenza should be determined according to the level of identification needed (influenza A or B versus influenza A and B), price, CLIA status, specimen type, staff familiarity with methods, turn-around-time, and relative sensitivity and specificity of the test.
T161	65797-66016	Epistemic_statement	denotes	For example, if the sensitivity and specificity of the test was 80%, and the prevalence of influenza was 5%, the positive predictive value (PPV) of the test would be 17%; if the prevalence was 20%, the PPV would be 50%.
T162	66136-66262	Epistemic_statement	denotes	When clinically important (for example, in hospitalized patients), negative rapid test results should be confirmed by culture.
T163	67838-68179	Epistemic_statement	denotes	Three types of mice can be used for such experiments: transgenic mice, where the gene encoding the molecule of interest is over-expressed or expressed in an abnormal location (tissue), knock-out mice, which have specific genes or gene segments deleted, and knock-in mice, which have mutated forms of the gene replacing the wild-type version.
T164	68481-68568	Epistemic_statement	denotes	These studies suggest that collectins regulate the innate and adaptive immune response.
T165	69483-69655	Epistemic_statement	denotes	Interferon may limit influenza virus dissemination for those strains that can replicate outside of the respiratory tract, a process that is more difficult to model in mice.
T166	70260-70397	Epistemic_statement	denotes	Recovery from infection can be mediated by the remaining adaptive immune response in conjunction with the ongoing innate immune response.
T167	70398-70531	Epistemic_statement	denotes	Ex-periments with these mice suggest that resistance to repeat infection and hetero-subtypic immunity is mediated in part by B cells.
T168	70532-70633	Epistemic_statement	denotes	The role of secretory antibodies has been studied using IgA, J chain, and poly-Ig receptor knockouts.
T169	70634-70875	Epistemic_statement	denotes	These studies have demonstrated that secretory IgA is not required for recovery from pulmonary infection but that secretory IgA may enhance clearance of homotypic and heterosubtypic virus from the upper respiratory tract following infection.
T170	71765-71854	Epistemic_statement	denotes	Immunologic memory in the respiratory tract may not be accurately reflected systemically.
T171	71855-72041	Epistemic_statement	denotes	With greater understanding of the innate and adaptive immune response, it may be possible to develop vaccines with improved efficacy or with the ability to modulate the pulmonary injury.
T172	72163-72269	Epistemic_statement	denotes	It is not known why some infected infants develop severe disease, whereas the majority have mild symptoms.
T173	72270-72439	Epistemic_statement	denotes	In response to infection, the host produces a complex mixture of cytokines and other inflammatory mediators with anti-viral but also potentially pathological properties.
T174	72440-72701	Epistemic_statement	denotes	Various clinical and experimental observations indicate that certain patterns of host response are associated with severe disease, but it has been extremely difficult to prove that these are causal determinants, rather than just correlates, of clinical outcome.
T175	72702-72854	Epistemic_statement	denotes	To better understand the association between clinical response to infection (phenotype) and specific genes, genetic association studies need to be done.
T176	72855-72944	Epistemic_statement	denotes	Genetic association studies can be done using a genome approach or using candidate genes.
T177	72945-73121	Epistemic_statement	denotes	It has been estimated that genomic approaches would require study of at least 200,000 markers in several thousand subjects, a project which would cost many millions of dollars.
T178	73189-73371	Epistemic_statement	denotes	Several candidate genes have been identified that may play a role in the immune response to RSV, including IL-5, 8, 10, and 13, CCR5, ICAM-1, IL-4 receptor, IFN-␥ and IFN-␥ receptor.
T179	73372-73565	Epistemic_statement	denotes	The primary objective of current genetic association studies is to identify host factors that contribute to the development of severe lower respiratory tract disease following infection by RSV.
T180	73566-73808	Epistemic_statement	denotes	These studies will address this problem through a molecular genetic approach, by investigating whether disease susceptibility is related to common polymorphisms in host genes that are thought to be critical for protection and/or pathogenesis.
T181	74194-74302	Epistemic_statement	denotes	We have previously demonstrated that IL-8 promoter polymorphisms may influence the level of gene expression.
T182	74303-74352	Epistemic_statement	denotes	IL8-251A is associated with severe bronchiolitis.
T183	74883-75125	Epistemic_statement	denotes	Our current work is directed at fine mapping of the IL8 bronchiolitis susceptibility effect; preliminary studies suggest there is also a link with a RAS effector gene (RASSF6) (OR 2.1) that is located just downstream from the IL-8 gene locus.
T184	75170-75318	Epistemic_statement	denotes	CCR5 is the major receptor for RANTES, MIP-1␣, and MIP-1␤ and has several polymorphisms that are associated with levels of CCR5 on the cell surface.
T185	75319-75394	Epistemic_statement	denotes	Certain polymorphisms of CCR5 have been associated with progression of HIV.
T186	75395-75567	Epistemic_statement	denotes	We have found that a CCR5 promoter SNP (single nucleotide polymorphism; CCR5-2459) is associated with more severe bronchiolitis (OR 1.5; OR 1.8 without other risk factors).
T187	75568-75761	Epistemic_statement	denotes	In combination, the studies on IL8 and CCR5 suggest that the innate immune response of the airway epithelial cells to infection with RSV appears to be important in determining disease severity.
T188	75762-75940	Epistemic_statement	denotes	Another area of interest in RSV pathogenesis relates to chromosome 5q31-33, which contains several markers that have been associated with atopy, IgE levels, and wheezing illness.
T189	76014-76159	Epistemic_statement	denotes	We have found that a common haplotype of IL-4, which 77% of humans carry, is associated with increased risk of severe RSV bronchiolitis (OR 1.5).
T190	76160-76398	Epistemic_statement	denotes	In a Korean study of 105 children under 24 months old with RSV lower respiratory tract infections and 315 blood donors, a different haplotype at IL-4 was also found to be associated with more severe disease (OR 1.63) (Choi et al., 2002) .
T191	76399-76566	Epistemic_statement	denotes	These results suggest that there may be a functional variant at this locus (identified by different haplotypes in different populations) that affects disease severity.
T192	76567-76749	Epistemic_statement	denotes	In addition, we have preliminary data that suggests that a rare haplotype of IL-13, found in only 5% of humans, also affects the risk of bronchiolitis after exposure to RSV (OR 2.0).
T193	76750-76916	Epistemic_statement	denotes	In conclusion, data from genetic association studies indicate that both innate and adaptive immune responses are important in determining the severity of RSV disease.
T194	76917-77112	Epistemic_statement	denotes	Genetic association studies should shed light on the pathogenesis of severe RSV disease, as well as providing information that may allow targeting of therapies to infants at especially high risk.
T195	77113-77286	Epistemic_statement	denotes	This approach could be extended to other common respiratory viral infections, such as those due to influenza and rhinovirus, to understand differences in disease expression.
T196	77962-78275	Epistemic_statement	denotes	These cells are grown on a support in culture and, upon the establishment of an air-liquid interface, differentiate into a multi-layered, pseudostratified, polarized tissue that closely resembles the airway epithelium in vivo with regard to morphology and functions, including mucus production and ciliary motion.
T197	78276-78333	Epistemic_statement	denotes	The cilia are limited to the apical surface of the cells.
T198	78334-78423	Epistemic_statement	denotes	Keratan sulfate is frequently present on ciliated cells and can detected immunologically.
T199	78424-78612	Epistemic_statement	denotes	Wild type recombinant RSV was genetically engineered to express the green fluorescent protein (rgRSV) from an added gene, so that infection could be monitored in real time in living cells.
T200	78613-78714	Epistemic_statement	denotes	rgRSV could only infect the cells when applied to the apical surface and not the basolateral surface.
T201	78806-79012	Epistemic_statement	denotes	Mechanical damage to the tissue, which exposes underlying layers of cells, did not increase the range of infection, indicating that this reflected an authentic tropism rather than simple physical exclusion.
T202	79702-79910	Epistemic_statement	denotes	Thirty-six days after rgRSV infection, intact infected cells were readily detected but, interestingly, cytopathologic effect was minimal, although cells were noted to become rounder in the vertical dimension.
T203	80023-80144	Epistemic_statement	denotes	RSV infection has minimal cytopathic effect with an absence of syncytia, likely due to polarized expression of F protein.
T204	80211-80290	Epistemic_statement	denotes	Like RSV, HPIV3 appears to infect, bud, and spread via the apical surface only.
T205	80291-80447	Epistemic_statement	denotes	HPIV3 also appeared to infect only ciliated cells, and appeared to infect keratin sulfate-containing cells, as well as a subset that lacked keratin sulfate.
T206	80548-80636	Epistemic_statement	denotes	Infection appeared to be completely dependent on sialic acid on the apical cell surface.
T207	80777-80934	Epistemic_statement	denotes	These model systems may help identify cellular receptors for RSV and HPIV3 and should be useful in studying the epithelial cell response to these infections.
T208	81029-81180	Epistemic_statement	denotes	Nosocomial S. aureus outbreaks have been linked to healthcare workers such that concern has been raised that S. aureus could be spread through the air.
T209	81181-81378	Epistemic_statement	denotes	Increased risk of S. aureus airborne transmission has been associated with increased S. aureus in the nose, male sex, snorting or sneezing, antibiotic use, cutaneous diseases, and viral infections.
T210	81733-81882	Epistemic_statement	denotes	The concept was expanded to include adults when an outbreak of S. aureus infections occurred in two newborn nurseries associated with a single nurse.
T211	81883-82098	Epistemic_statement	denotes	During the outbreak investigation, it was noted that the likelihood of this nurse transmitting S. aureus increased five-fold during periods of time when she had an upper respiratory infection (Belani et al., 1986) .
T212	82099-82251	Epistemic_statement	denotes	The possibility that "cloud adults" exist was substantiated during an investigation of another point-source outbreak of S. aureus nosocomial pneumonias.
T213	82530-82710	Epistemic_statement	denotes	Following rhinovirus infection, there was a 40-fold increase in airborne dispersal of S. aureus and this increase could be decreased 75% by wearing a mask (Sherertz et al., 1996) .
T214	83390-83589	Epistemic_statement	denotes	Masks did not blunt this effect but wearing barrier garb (gown, gloves, booties, cap) did, suggesting that in most volunteers the airborne dispersal is not coming in real time directly from the nose.
T215	83906-84103	Epistemic_statement	denotes	Recent studies have shown that coagulase-negative Staphylococci have increased airborne dispersal after a rhinovirus infection suggesting that the "cloud phenomenon" may occur with other organisms.
T216	84104-84379	Epistemic_statement	denotes	This finding may be quite important as it suggests a possible mechanism for the outbreaks of meningococcal, pneumococcal, and streptococcal (Group A) infection that occur in the community and in semi-closed populations as an aftermath to outbreaks of influenza and viral URI.
T217	84380-84674	Epistemic_statement	denotes	One potential hypothesis to explain the pathogenesis of the "cloud adult" is that infection results in inflammation that in turn reduces the diameter of the nasal passage and increases the rate of airflow and associated aerosolization of particulates, including bacteria, by the venturi effect.
T218	84675-84832	Epistemic_statement	denotes	To test this hypothesis, volunteers with allergic rhinitis who had their medication held but did not have culturable virus were placed into the test chamber.
T219	84920-85040	Epistemic_statement	denotes	The inflammatory response in the nose, not the rhinovirus itself, may be central to the mechanism of airborne dispersal.
T220	85041-85246	Epistemic_statement	denotes	Imperial College, London, UK) RSV bronchiolitis in infancy is strongly associated with the later development of asthma (Stein et al., 1999) and RSV is also implicated in virus induced asthma exacerbations.
T221	85477-85621	Epistemic_statement	denotes	Recent evidence suggests that virus-induced asthma exacerbations may be associated with deficient type 1 immunity (Papadopoulos et al., 2002d) .
T222	86359-86515	Epistemic_statement	denotes	We hypothesized that in a type 2 cytokine rich environment (as occurs in asthmatic airways), virus-induced production of type 1 cytokines is down-regulated.
T223	86516-86652	Epistemic_statement	denotes	To test this hypothesis, we studied RSV-induced production of IL-15 in respiratory epithelial cells in the absence and presence of IL-4.
T224	87002-87241	Epistemic_statement	denotes	Decreased production of IL-15 in the lung in respiratory viral infections in asthmatic subjects may be a possible pathway for deficient antiviral immune responses, delayed virus eradication and virus-induced exacerbations of atopic asthma.
T225	87981-88375	Epistemic_statement	denotes	Wheezing can be classified into four types, predominating at distinct ages: transient infant wheeze (likely related to exposure to smoke or small lungs); early wheeze (typically after a viral illness); classical atopic asthma (which tends to be familial) and chronic obstructive airway disease (typically resulting from chronic irritant exposure, such as smoke, throughout a person's lifetime).
T226	88895-89029	Epistemic_statement	denotes	As a result of this significant burden, many have studied asthma and its relationship to respiratory viral diseases, particularly RSV.
T227	90039-90370	Epistemic_statement	denotes	To further investigate a potential link between RSV bronchiolitis and asthma, Wenzel and colleagues conducted a long-term follow-up study of 13 children with bronchopulmonary dysplasia (PBD) who were treated with RSV polyclonal immunoglobulin (RSV-Ig) during infancy and 26 age-matched controls with BPD who did not receive RSV-Ig.
T228	90519-90782	Epistemic_statement	denotes	However, 7-10 years after enrollment, RSV-Ig treated children had significantly better FEV1/FVC ratios and airway conductance, in addition to less atopy, missed school, colds, asthma attacks, hospitalizations, and use of asthma medications (Wenzel et al., 2002) .
T229	90783-91008	Epistemic_statement	denotes	These results raised the question of whether normal lungs become asthmatic after viral infection or if weakened lungs that would become asthmatic without infection are also at increased risk of wheezing after viral infection.
T230	91878-92065	Epistemic_statement	denotes	Taken together, these results suggest that mild infection results in low level IFN-␥ production, while bronchiolitis results in increased IL-4 production in addition (Pala et al., 2002) .
T231	92066-92146	Epistemic_statement	denotes	The age of acquisition of RSV infection may impact on future asthmatic sequelae.
T232	92460-92663	Epistemic_statement	denotes	Such immune maturation hypotheses have been documented by stimulating tonsil extracts from children with RSV and PHA in vitro; these stimulations result in increasing levels of IFN-␥ with increasing age.
T233	92664-92929	Epistemic_statement	denotes	When mice are infected with RSV at 1 day, 1, 4, and 8 weeks of age and then reinfected at 12 weeks of age, infection of older mice resulted in increased viral load, likely secondary to larger lungs with more cells to infect, but similar rates of clearance of virus.
T234	93398-93505	Epistemic_statement	denotes	This data suggests that the nature of the secondary response is determined by the age at primary infection.
T235	93506-93669	Epistemic_statement	denotes	RSV infection early in life sensitizes for severe response to viral challenge later in life and T-cell priming in the neonatal period may explain this association.
T236	93670-93820	Epistemic_statement	denotes	Delaying RSV infection beyond infancy could have long-term benefits in terms of less severe disease, decreased atopy, and lower frequencies of asthma.
T237	93821-94062	Epistemic_statement	denotes	Potential mechanisms for this delayed effect include chronic, persistent, or latent viral infection, remodeling of the lung after infection, permanent epithelial damage, immunologic priming or tolerance, or bystander antigenic sensitization.
T238	94063-94134	Epistemic_statement	denotes	Further studies will need to be done to investigate these alternatives.
T239	94135-94322	Epistemic_statement	denotes	Several studies suggest that some infections in infancy protect against asthma and allergic disease while lower respiratory tract viral illness are associated with wheezing later in life.
T240	94323-94558	Epistemic_statement	denotes	In general infections induce type 1 responses (IFN-␣, IL-12, IL-15, IL-18, IFN-␥) while allergic disorders are associated with type 2 responses (IL-4, IL-5, IL-9, and IL-13); type 1 and type 2 responses are mutually counter-regulatory.
T241	94559-94769	Epistemic_statement	denotes	Immune responses at birth are skewed toward type 2, and microbial exposure is required to develop type 1 responses, so environmental exposure early in life likely contributes to maturation of the immune system.
T242	94969-95114	Epistemic_statement	denotes	Likewise, hepatitis A, likely a marker of load of infectious exposure, is associated with decreased risk of allergies (Matricardi et al., 2002) .
T243	95115-95233	Epistemic_statement	denotes	Respiratory virus infections have been associated with an increased risk of wheezing illness and atopic sensitization.
T244	95787-95966	Epistemic_statement	denotes	However, lower respiratory tract illnesses resulting from other virus types were also significantly associated with increased risk of wheezing later in life (Stein et al., 1999) .
T245	96093-96416	Epistemic_statement	denotes	Potential explanations for the relationship of early virus-related lower respiratory illness including RSV bronchiolitis is that patients with lower respiratory illness/bronchiolitis may have smaller airways, deficient type 1 or increased type 2 immunity, or develop increased allergen sensitization during acute infection.
T246	96417-96665	Epistemic_statement	denotes	To evaluate these potential explanations, Legg and associates collected nasal lavages on days 1, 2 and 5-7 of illness and peripheral blood mononuclear cells on days 5-7 of illness from children in their first year of life with proven RSV infection.
T247	97019-97187	Epistemic_statement	denotes	From these results, the authors concluded that RSV bronchiolitis is associated with deficient type 1 immunity and impaired virus clearance (Mallia and Johnston, 2002) .
T248	97653-97934	Epistemic_statement	denotes	In conclusion, it appears that the risk of allergic disease later in life can be reduced by high overall load of infectious disease (including respiratory viral infections) early in life, but exposure to respiratory infections early in life causes increased morbidity at that time.
T249	97935-98202	Epistemic_statement	denotes	Likewise, individual infections in subjects at risk, such as those with deficient type 1 immunity or small airways, result in infections that are more severe, more likely to involve the lower respiratory tract, and are strongly associated with wheezing later in life.
T250	98379-98529	Epistemic_statement	denotes	Serious illness due to respiratory viruses appears most common in hematopoietic stem cell transplant (HSCT) recipients and lung transplant recipients.
T251	99055-99219	Epistemic_statement	denotes	Our retrospective review found that respiratory viral pneumonia was associated with an increased risk of death (HR 2.2 for RSV, 3.4 for PIV, and 2.4 for influenza).
T252	99354-99490	Epistemic_statement	denotes	This finding suggests that the clinical effects of RVIs are likely both from direct lytic effects and indirect immunomodulatory effects.
T253	99743-100013	Epistemic_statement	denotes	Season, male sex, and transplant type were associated with increased risk of developing RSV infection; unrelated donor status was associated with PIV infection; and season, female sex, and underlying malignancy were associated with increased risk of influenza infection.
T254	100014-100164	Epistemic_statement	denotes	Data from other studies suggest that CD4 lymphopenia also enhances the risk of acquisition of a respiratory viral illness in a dose-dependent fashion.
T255	100165-100266	Epistemic_statement	denotes	Lymphopenia is also associated with increased risk of progression to lower respiratory tract disease.
T256	100692-100806	Epistemic_statement	denotes	Unfortunately, it is not yet possible to determine accurately which patients will progress to lower tract disease.
T257	101771-102116	Epistemic_statement	denotes	Better results have been documented with aerosolized ribavirin alone (22-66% survival) (Harrington et al., 1992; Ljungman et al., 2001) , or in combination with IVIG (50-68% survival) (Ghosh et al., 2001; Ljungman et al., 2001; Whimbey et al., 1995) , RSV-Ig (86-91% survival) (DeVincenzo et al., 2000; Small et al., 2002) or palivizumab (83%) .
T258	102117-102254	Epistemic_statement	denotes	These data suggest that optimal therapy for RSV pneumonia involves the combination of aerosolized ribavirin plus an antibody preparation.
T259	102470-102734	Epistemic_statement	denotes	Potential risk factors for increased mortality in patients with RSV pneumonia includes the co-pathogens, concomitant immunosuppression (steroids, anti-lymphocyte antibodies), lymphopenia, preexisting lung disease, and the therapy used, including the time of onset.
T260	102735-102814	Epistemic_statement	denotes	Prevention strategies should be explored to limit the frequency of RSV disease.
T261	102954-103152	Epistemic_statement	denotes	Use of RSV-Ig or palivizumab for prophylaxis might be beneficial, although the two preparations have never been studied in this population in a randomized fashion and would be very expensive to use.
T262	103153-103373	Epistemic_statement	denotes	Preemptive therapy, with aerosolized ribavirin, could be used in patients with asymptomatic shedding or RSV URIs, although early detection methods limit the ability to implement preemptive management of these infections.
T263	103374-103466	Epistemic_statement	denotes	Additionally, these preemptive strategies have not been tested for RSV in randomized trials.
T264	103467-103622	Epistemic_statement	denotes	As a result of the potentially devastating outcome of RSV and other RVIs, there has been some concern about the need to delay HSCT in symptomatic patients.
T265	104821-104933	Epistemic_statement	denotes	Thus, delay of transplant for at least 1 month should be advised for all myeloablative transplants (CDC, 2000) .
T266	106484-106657	Epistemic_statement	denotes	This study prospectively confirmed that RSV occurs typically in the winter months, can be nosocomially transmitted, and can frequently progress to involve the lower airways.
T267	106734-106870	Epistemic_statement	denotes	RSV infection was associated with a low mortality in this heterogeneous population, despite 33% having lower respiratory tract symptoms.
T268	107942-108159	Epistemic_statement	denotes	A potential causative viral agent was found in 88.7% of cases: RSV 27%, entero-25%, rhino-22%, nontypable picorna-16.4%, adenovirus 5%, hMPV 4%, parainfluenza type 1/3 5%, influenza A and B both 1% and coronavirus 1%.
T269	108488-108587	Epistemic_statement	denotes	RVIs were associated with almost all episodes of wheezing leading to hospitalization in this study.
T270	108588-108791	Epistemic_statement	denotes	This study was also one of the first to demonstrate the contribution of hMPV, particularly during winter epidemics, and its correlation with wheezing (Jartti et al., 2002b; van den Hoogen et al., 2001) .
T271	109868-110006	Epistemic_statement	denotes	The avian influenza H5N1, H9N2, H5N2, H7, and H6 subtypes have recently been identified as high priority for pandemic vaccine development.
T272	111223-111268	Epistemic_statement	denotes	Early studies of this candidate are on-going.
T273	111599-111729	Epistemic_statement	denotes	It is hoped that these and future studies will allow the development of seed lots of vaccine viruses for a range of avian viruses.
T274	111730-111895	Epistemic_statement	denotes	Additionally, alternative substrates for vaccine production and new adjuvants will need to be tested to enhance our armamentarium against pandemic influenza strains.
T275	113139-113352	Epistemic_statement	denotes	From the interim analysis of the first year's data, it appears that CAIV-T confers substantial efficacy against culture-confirmed influenza in Asian children, despite regional differences in influenza circulation.
T276	113353-113457	Epistemic_statement	denotes	Additional data about the impact on AOM and the results of the second year of the study are in progress.
T277	113710-113818	Epistemic_statement	denotes	Approval of the CAIV-T vaccine was slow because of concerns about safety and efficacy in certain age groups.
T278	113819-114012	Epistemic_statement	denotes	The vaccine has been shown to be genetically stable; viruses that have lost their temperature sensitivity or cold-adaptation RNA Virus Virosome have not been recovered from vaccinated patients.
T279	114013-114208	Epistemic_statement	denotes	Likewise, transmission of the vaccine virus is very infrequent; only one case has been documented in which a child in a day care setting acquired the vaccine strain from another vaccinated child.
T280	114318-114507	Epistemic_statement	denotes	The two major concerns on the part of the FDA after their initial advisory panel review in 2001 related to the questions of increased risk of pneumonia and asthma in vaccinated individuals.
T281	115180-115381	Epistemic_statement	denotes	The FDA advisory committee felt that there was adequate data on the efficacy and safety of the vaccine in children >59 months of age and adults younger than 50 to recommend approval for this age group.
T282	115382-115553	Epistemic_statement	denotes	As a result, further studies are needed in the age groups that have not been as completely studied, including young children and otherwise healthy adults aged 50-64 years.
T283	115554-115708	Epistemic_statement	denotes	Virosomes are functionally reconstituted, non-infectious viral envelopes retaining the cell entry properties of the native virus but lacking the RNA core.
T284	116352-116559	Epistemic_statement	denotes	Antigens may also be encapsulated within the lumen of the virosome, so that delivery of the antigen occurs intracellularly and the immune system can react against both the antigen within and on the virosome.
T285	116560-116871	Epistemic_statement	denotes	Theoretically, once taken up by an antigen presenting cell (APC), the virosome would fuse from within the acidic endosomal cell compartment, resulting in delivery of virosome-encapsulated antigen to the cell cytosol, while surface-associated antigen-including part of the HA-would remain behind in the endosome.
T286	116872-116934	Epistemic_statement	denotes	In the cytosol, the antigen would be processed by proteasomes.
T287	116935-117114	Epistemic_statement	denotes	Peptides produced would bind in the ER to MHC class I molecules to be ultimately presented on the APC surface, priming CD8 + T cells to mature into cytotoxic T lymphocytes (CTLs).
T288	117115-117263	Epistemic_statement	denotes	Within the endosome, virosomal antigen would be degraded to allow peptides to bind to MHC class II molecules and activate CD4 + T helper cells (Fig.
T289	118204-118488	Epistemic_statement	denotes	Despite a concern that pre-existing antibodies against HA would block virosome-mediated CTL priming, mice with a high pre-existing antibody titer against virosomal HA developed a strong ovalbumin-specific CTL response after subsequent immunization with ovalbumin-containing virosomes.
T290	118489-118608	Epistemic_statement	denotes	It appears that antibody-opsonized virosomes are actively processed by dendritic cells through uptake via Fc receptors.
T291	119056-119211	Epistemic_statement	denotes	As a result of their broad activation of the immune system and their ability to carry antigens, virosomes hold significant promise for vaccine development.
T292	119212-119372	Epistemic_statement	denotes	Virosomes could also be used as a platform for inclusion of immunomodulators or adjuvants to be used as potential intranasal and/or pandemic influenza vaccines.
T293	119373-119538	Epistemic_statement	denotes	Newer influenza virosome vaccines could be supplemented with other influenza antigens, such as the NP, M1, or M2, for further induction of humoral and CTL responses.
T294	119539-119652	Epistemic_statement	denotes	Potential other applications include vaccine development for bioterrorism agents and therapeutic cancer vaccines.
T295	119894-119988	Epistemic_statement	denotes	Fifteen clinical studies with 2970 patients have been done on the vaccine, called Influvac ® .
T296	119989-120087	Epistemic_statement	denotes	The vaccine has been well tolerated and is at least as effective as conventional subunit vaccines.
T297	120245-120470	Epistemic_statement	denotes	FluINsure TM is a trivalent, subunit influenza vaccine for intranasal inoculation that is composed of inactivated, partially-purified influenza antigens in non-covalent complex with the Proteosome TM adjuvant/delivery system.
T298	120769-120977	Epistemic_statement	denotes	The process has been shown adaptable to egg-grown, detergent-split antigens inactivated by either formalin or ␤-propiolactone, and can also be used with recombinant antigens generated in a baculovirus system.
T299	121173-121319	Epistemic_statement	denotes	Although initially formulated with thimerosal, a preservative-free, 0.22 m filterable product packaged in a unit dose device is under development.
T300	121637-121765	Epistemic_statement	denotes	While intranasal influenza antigens alone may induce some secretory responses, FluINsure TM is 1-2 orders of magnitude superior.
T301	121766-121894	Epistemic_statement	denotes	In addition, FluINsure TM is associated with IgG1: IgG2a ratios suggestive of a Th1-shifted response similar to virus infection.
T302	121895-122149	Epistemic_statement	denotes	This correlates with the observation that spleen cells of animals immunized with nasal FluINsure TM produce the same amount of IFN-␥ as those of animals immunized with IM vaccine when restimulated with virus in vitro, but much less IL-5 (a Th2 cytokine).
T303	122150-122413	Epistemic_statement	denotes	FluINsure TM can protect mice against a lethal respiratory challenge with mouse-adapted homologous virus in a manner indistinguishable from IM vaccine, and also protects ferrets against fever and/or virus shedding following challenge with recent epidemic strains.
T304	122704-122807	Epistemic_statement	denotes	Monovalent prototype and trivalent data are highly consistent regarding both immunogenicity and safety.
T305	123806-124017	Epistemic_statement	denotes	Overall, immune responses to influenza A/H1N1 and A/H3N2 antigens have been quite consistent across multiple studies and lots, whereas responses to B antigens (as with many influenza vaccines) are more variable.
T306	124018-124196	Epistemic_statement	denotes	In trivalent studies performed to date, potentially protective immune responses have been seen in 70-80% for A/H1N1 strains, 70-90% for A/H3N2 strains, and 40-100% for B strains.
T307	124197-124359	Epistemic_statement	denotes	In summary, the FluINsure TM proteosome intranasal influenza vaccine appears to be a promising candidate as it is inexpensive and easily adaptable to new viruses.
T308	124360-124420	Epistemic_statement	denotes	It appears to be safe and immunogenic in animals and humans.
T309	124742-124925	Epistemic_statement	denotes	Studies in adults have demonstrated that the Inflexal V is equal to conventional inactivated influenza vaccine (Fluarix) in terms of immunogenicity and appears to be better tolerated.
T310	125326-125555	Epistemic_statement	denotes	Finally, a non-virosomal intranasal influenza vaccine that used Escherichia coli heat-labile toxin as an adjuvant, previously manufactured by Berna, was removed from the market because of a possible association with Bell's Palsy.
T311	125771-125861	Epistemic_statement	denotes	Although the incidence was low, the company decided to remove the product from the market.
T312	126096-126214	Epistemic_statement	denotes	Preliminary studies of the immunogenicity and tolerability have been undertaken in 40 healthy adults aged 18-45 years.
T313	126685-126838	Epistemic_statement	denotes	This study showed that the vaccine was safe and immunogenic, although annual vaccination would likely be required to maintain protective antibody levels.
T314	127197-127313	Epistemic_statement	denotes	Revaccination was immunogenic suggesting that annual vaccination may allow the maintenance of protective antibodies.
T315	129869-130078	Epistemic_statement	denotes	The overall tolerance profile was favorable, and an independent Experts Board recommended that clinical development should be continued, but with increased safety documentation in the phase III efficacy study.
T316	130699-130832	Epistemic_statement	denotes	In conclusion, these data indicate that BBG2Na + alum is immunogenic in the elderly and that a single dose regimen probably suffices.
T317	130833-130927	Epistemic_statement	denotes	However, safety monitoring would be an essential component for the phase III efficacy studies.
T318	132688-132814	Epistemic_statement	denotes	The young infants had minimal antibody responses, although there were detectable serum levels of IgG and IgA to the G protein.
T319	132926-133111	Epistemic_statement	denotes	A second dose of vaccine, the response to which can be used as a surrogate for reinfection, resulted in rare shedding of the virus and no evidence of enhanced RSV illness once infected.
T320	133112-133217	Epistemic_statement	denotes	These findings suggest that the vaccine may be protective without detectable increases in antibody level.
T321	133218-133479	Epistemic_statement	denotes	Finally, a NS-2 protein deleted 248/404 virus, a change that may make the virus more susceptible to interferon, has been found to have markedly reduced viral shedding, particularly in seronegative children, when compared to the other attenuated vaccine strains.
T322	133480-133672	Epistemic_statement	denotes	Although the study of these live-attenuated vaccines against RSV have given limited information about efficacy, they have given significant data to support continued develop of these vaccines.
T323	133752-134049	Epistemic_statement	denotes	One study found that 100% of children 0-12 years of age had experienced PIV3 infections and that ∼60% of children age 13-24 months and ∼35% of children age 25-36 months were later reinfected with the same strain, suggesting incomplete protection following primary infection (Glezen et al., 1984) .
T324	134050-134364	Epistemic_statement	denotes	Two different PIV3 vaccines are currently under development with the goal of preventing PIV-associated lower respiratory tract illness in those at risk: a live-attenuated bovine vaccine, which is being developed by MedImmune and NIH, and a cp45-based vaccine that is being developed cooperatively by Wyeth and NIH.
T325	134365-134585	Epistemic_statement	denotes	Although bovine PIV3 was well tolerated when used to vaccinate infants and children, only 70% of vaccinated children developed a four-fold rise in antibody titer, far less than would be seen with natural HPIV3 infection.
T326	135224-135527	Epistemic_statement	denotes	Additional potential uses of these recombinant PIV-3 viruses are as vectors to express PIV-1 and RSV F and G proteins, measles H protein, or surface glycoproteins of other respiratory viruses Durbin et al., 2000; Schmidt et al., 2000 Schmidt et al., , 2002 Skiadopoulos et al., 2001; Tao et al., 2000) .
T327	136141-136237	Epistemic_statement	denotes	This suggests that prior natural HPIV3 infection limits the infectiousness of the vaccine virus.
T328	136441-136662	Epistemic_statement	denotes	In these studies, the vaccine was well tolerated without significant adverse effects, although a small number of URIs and an increased number of otitis media episodes were observed in the phase I but not phase II studies.
T329	136663-136793	Epistemic_statement	denotes	Next, a two-dose study in 1-2-month-old infants was conducted, with the second dose being used as a surrogate challenge infection.
T330	137459-137729	Epistemic_statement	denotes	All five formed plaques at 39 • C, represented a small fraction (1%) of the total viral population, presented at the peak of viral shedding and were cleared at the same rate as fully temperature-sensitive viruses, and were not associated with changes in clinical status.
T331	137730-137884	Epistemic_statement	denotes	From these studies, it is clear that the cp45 HPIV3 vaccine is well-tolerated and immunogenic in infants and children but uncommonly may partially revert.
T332	137885-137990	Epistemic_statement	denotes	Multiple doses will be needed in infancy and the interval between doses should not be more than 2 months.
T333	139130-139260	Epistemic_statement	denotes	Further studies are planned to investigate the incidence of OM and the utility of two doses of both PIV3 and combination vaccines.
T334	139554-139671	Epistemic_statement	denotes	The intranasally administered vaccine has been shown previously to be safe and well tolerated in adults and children.
T335	140692-140811	Epistemic_statement	denotes	This LIV that is currently used in Russian appears to be safe, well tolerated, and effective in children 3-6 years old.
T336	141210-141370	Epistemic_statement	denotes	The H9N2 virus exhibits receptor-binding properties consistent with other human influenza viruses suggesting that this virus could potentially cause a pandemic.
T337	141431-141602	Epistemic_statement	denotes	Since whole virus vaccines may be more immunogenic in naïve patients, whole virion (WV) and subunit (SV) vaccines were prepared using influenza A/Hong Kong/0173/99 (H9N2).
T338	141978-142153	Epistemic_statement	denotes	Both vaccines were well tolerated, although the WV was associated with more frequent pain (42% versus 10%), nausea (15% versus 0%), and arthalgias (15% versus 3%) than the SV.
T339	142154-142327	Epistemic_statement	denotes	There were no differences in seroconversion between WV and SV at day 42, although seroconversion was more likely in patients who had received 30 g, particularly with the WV.
T340	142328-142439	Epistemic_statement	denotes	Patients younger than 32 years were less likely to convert after the first dose than following the second dose.
T341	142440-142536	Epistemic_statement	denotes	This suggests that a booster dose will be required for all naïve patients younger than 32 years.
T342	143508-143704	Epistemic_statement	denotes	Studies of these agents are difficult because it is unclear what are the optimal dose and formulation of Echinacea to use and what are the relative absorption and distribution of each preparation.
T343	144276-144472	Epistemic_statement	denotes	In summary, activities of Echinacea extracts are unclear, the products are not standardized, and the currently available studies provide limited data that can be generalized to different products.
T344	144473-144586	Epistemic_statement	denotes	Components of the pathogenesis of rhinoviral colds need to be considered as targets for therapeutic intervention.
T345	144847-144918	Epistemic_statement	denotes	Progression of the virus to the lower respiratory tract may also occur.
T346	144919-145002	Epistemic_statement	denotes	One step amenable to modification may be the oxidative stress induced by the virus.
T347	145420-145527	Epistemic_statement	denotes	NAC exposure was associated with significant decreases in NFB and IL-8 in a concentration-dependent manner.
T348	145699-145961	Epistemic_statement	denotes	Anti-ICAM exposure of cell culture was associated with a significant decrease in viral titer, but there was no difference in IL-8 production in wells exposed and unexposed to anti-ICAM, suggesting that elaboration of IL-8 is independent of viral binding to ICAM.
T349	147150-147310	Epistemic_statement	denotes	Future studies will be directed at specific inhibitors of NOX-4 to assess their ability to limit the viral titer and symptoms as the result of these infections.
T350	147651-147828	Epistemic_statement	denotes	Unfortunately, it had to be given in high doses six times a day to be effective, and has not been pursued for clinical development (Huguenel et al., 1997; Turner et al., 1999) .
T351	147829-148026	Epistemic_statement	denotes	A murine monoclonal antibody, termed RRMA, which blocked ICAM-1, was found to be safe in humans and partially effective in preventing experimental hRV infection in one trial (Hayden et al., 1988) .
T352	149157-149365	Epistemic_statement	denotes	The molecule is stable for over 3 months at 37 • C and for over a week in nasal mucus at 37 • C. As a result of these promising studies, the compound is being developed as an intranasal anti-rhinovirus agent.
T353	149654-149840	Epistemic_statement	denotes	CV-N is active in vitro against influenza but has little or no activity against adenovirus, parainfluenza virus, respiratory syncytial virus, enterovirus, rhinovirus, or coxsackie virus.
T354	150189-150340	Epistemic_statement	denotes	Europium-labeled CV-N bound to viral HA that contained high mannose residues, and exogenous oligomannose-8 could inhibit the binding of CV-N to the HA.
T355	151202-151541	Epistemic_statement	denotes	Ruprintrivir (AG7088) (Amy Patick, Pfizer Global Research and Development, La Jolla, CA) In the search for drugs active against picornaviruses, the 3C protease was identified as a important target because it lacks similarity to human proteases, is essential for replication, and has a highly conserved active site (Matthews et al., 1994) .
T356	154117-154239	Epistemic_statement	denotes	Pleconaril treatment was associated with a reduction in illness duration of 0.6 and 1.5 days in each study, respectively .
T357	154958-155139	Epistemic_statement	denotes	Three-and-a-half percent of women on oral contraceptives developed menstrual disorders after using pleconaril, although there was no increased incidence of pregnancy in these women.
T358	155761-155966	Epistemic_statement	denotes	The safety profile of pleconaril in this study was similar to the treatment study, although there was a two-to three-fold increased rate of menstrual disorders in pleconaril recipients compared to placebo.
T359	156193-156333	Epistemic_statement	denotes	This increased CYP3A activity was associated with a 35% decrease in the AUC of ethinyl estradiol and a 28% decrease in the AUC of midazolam.
T360	156435-156611	Epistemic_statement	denotes	It is interesting to note that there was no evidence that pleconaril had an impact on the cytochrome P450 system in preliminary studies in rat, dog, or human hepatocyte assays.
T361	156612-156934	Epistemic_statement	denotes	Although the FDA Advisory Panel that reviewed the application for pleconaril agreed that it was efficacious, there were concerns about drug interactions, development of antiviral resistance, its probable over-the-counter-like use if approved, and the generalizability of the available efficacy data to higher risk persons.
T362	156935-157021	Epistemic_statement	denotes	As a result of these concerns, the FDA deemed pleconaril not approvable in June, 2002.
T363	157518-157787	Epistemic_statement	denotes	Currently, pharmaceutical interest in compounds with activity against respiratory viruses is limited because of a focus on chronic disease, unattractive commercial opportunities, and the high standard required to obtain FDA approval for non-life-threatening conditions.
T364	157788-157959	Epistemic_statement	denotes	Despite these limitations, colds are the most common reason for seeing a physician and result in nearly 75% of patients taking over-the-counter medications or antibiotics.
T365	157960-158168	Epistemic_statement	denotes	Antiviral agents with activity against rhinoviruses are needed and may have additional benefits such as reducing the indiscriminant use of antibiotics with its resultant induction of antimicrobial resistance.
T366	158169-158391	Epistemic_statement	denotes	As has been described earlier, RSV is an important pathogen in infants, the elderly, and the immunocompromised and is responsible for over 100,000 excess hospitalizations and US$ 2 billion in direct medical costs annually.
T367	158392-158481	Epistemic_statement	denotes	Several compounds are under development that may be effective in treating RSV infections.
T368	158482-159018	Epistemic_statement	denotes	One such class of compounds inhibits RSV replication by affecting functions associated with the viral fusion (F) glycoprotein: Janssen's R170591, a topically applied compound with a reported EC 50 against RSV of <1 nM, is in preclinical study; Bristol-Myers Squibb's BMS-433771, an orally bioavailable compound with a reported EC 50 against RSV of 10 nM, is in preclinical study; and ViroPharma's VP14637, a compound delivered by small particle aerosol (SPA) inhalation with an EC 50 against RSV of <1 nM, is completing phase 1 studies.
T369	159091-159238	Epistemic_statement	denotes	In vitro time of drug addition studies suggest that the drug has to be present early after infection to affect a single round of virus replication.
T370	160044-160179	Epistemic_statement	denotes	A phase 1 study has recently been completed, although data analysis is ongoing, and other studies are in the planning stages currently.
T371	160180-160481	Epistemic_statement	denotes	(Mikhail Matrosovich, Philipps University, Marburg, Germany) Influenza virus can develop resistance to neuraminidase inhibitors via changes in the neuraminidase (NA), which results in decreased drug binding, or in the hemagglutinin (HA), which results in lowered HA affinity for its cellular receptor.
T372	160482-160595	Epistemic_statement	denotes	To detect both types of resistance, and perhaps novel ones, a virus inhibition assay in cell culture is required.
T373	160596-160925	Epistemic_statement	denotes	Unfortunately, current cell culture assays are not predictive of influenza virus sensitivity to neuraminidase inhibitors (NAI) in enzyme inhibition assays or in vivo (McKimm-Breschkin, 2000; Tisdale, 2000) NAI sensitive strains may appear to be resistant, while NAI resistant mutants may show susceptibility with current methods.
T374	160926-161057	Epistemic_statement	denotes	One reason for this limitation is that laboratory cell lines do not model influenza virus receptors in the human airway epithelium.
T375	161784-161940	Epistemic_statement	denotes	Preliminary studies demonstrated that the transfection was stable and resulted in substantially increased two to six linked sialic acid on the cell surface.
T376	162615-162715	Epistemic_statement	denotes	The drug susceptibility patterns correlated with the affinity for 6-linked receptors of the viruses.
T377	162716-162914	Epistemic_statement	denotes	In summary, the SIAT-transfected MDCK cells have acquired genes that are stably expressed and result in increased expression of 6-linked sialic acids and reduced expression of 3-linked sialic acids.
T378	163231-163344	Epistemic_statement	denotes	The SIAT1 transfected MDCK cells appear to be a promising system for testing influenza virus sensitivity to NAIs.
T379	164042-164284	Epistemic_statement	denotes	The Neuraminidase Inhibitor Susceptibility Network (NISN) was established to monitor the potential development of resistance in clinical isolates with the widespread introduction of NA inhibitors into clinical practice (Zambon et al., 2001) .
T380	164573-164802	Epistemic_statement	denotes	Preliminary testing showed that the MUNANA fluorescent assay (Potier et al., 1979) and NA-STAR chemiluminescent assay (Buxton et al., 2000) gave similar results, although the NA-STAR method was preferred when NA activity was low.
T381	165454-165641	Epistemic_statement	denotes	One of 10 N1, 7 of 38 N2, and 1 of 42 influenza B isolates had D151 to N, G, E, or V. Originally the D151 was thought to be the proton donor for the catalytic reaction mediated by the NA.
T382	165642-165748	Epistemic_statement	denotes	Since none of these isolates showed decreased enzyme activity, the D151 likely does not provide this role.
T383	165749-165961	Epistemic_statement	denotes	In addition to changes in non-conserved residues associated with natural antigen drift, there was also a change in the conserved residue T225I in 1 B virus, and co-evolution of I203L and E375G in 5/42 B isolates.
T384	165962-166124	Epistemic_statement	denotes	Molecular modeling shows these latter two residues lie on opposite sides of the NA head and hence are more likely to be random rather than compensatory mutations.
T385	166125-166246	Epistemic_statement	denotes	Importantly, despite sequence variations, there was no naturally occurring resistance to either zanamivir or oseltamivir.
T386	166252-166618	Epistemic_statement	denotes	Effect of mutations in the hemagglutinin gene of influenza A viruses on the resistance phenotype of neuraminidase inhibitors (Guy Boivin, Laval University, Québec, Canada) Previous studies have shown that resistance to neuraminidase inhibitors (NAI) generated after in vitro passages may result in mutations in the neuraminidase (NA) and/or hemagglutinin (HA) genes.
T387	166619-166734	Epistemic_statement	denotes	However, the effect of HA mutations alone on the resistance phenotype remains to be confirmed in clinical isolates.
T388	167501-167633	Epistemic_statement	denotes	This data suggests that in vitro generated resistance to NAIs may not be solely attributable to HA mutations as previously reported.
T389	167634-167786	Epistemic_statement	denotes	In addition, the combined effects of HA and NA mutations needs to be investigated as potential mechanisms for NAI resistance (Nedyalkova et al., 2002) .
T390	168116-168304	Epistemic_statement	denotes	Two additional orally active neuraminidase inhibitors (NAI), peramivir and A-315675, are investigational, although there are no current plans to move these agents forward for clinical use.
T391	168305-168515	Epistemic_statement	denotes	In vitro resistance can be mediated by changes in the hemagglutinin (HA), which is strain-specific, change in neuraminidase (NA), which is both subtype-and drug-specific, both, or by creation of a defective NA.
T392	168718-168888	Epistemic_statement	denotes	These results of these assays are affected if the reaction conditions are varied, even slightly, if there are mixtures of variants present, or if the NA has low activity.
T393	168889-169025	Epistemic_statement	denotes	Resistance may be defined as a 5-10-fold or greater increase in the IC 50 values compared to the virus recovered prior to drug exposure.
T394	169026-169153	Epistemic_statement	denotes	Sequencing of the NA or HA genes can be done to document genetic changes that may be associated with the phenotypic resistance.
T395	169442-169589	Epistemic_statement	denotes	However, several oseltamivir-selected changes in the NA of influenza A viruses have been detected: N1 H274T and N2 G119V and R292K have been found.
T396	172042-172260	Epistemic_statement	denotes	Over time, a G119V NA mutation occurred which conferred resistance to oseltamivir only and an S31N M2 mutation conferred M2 inhibitor resistance, so that a virus resistant to both M2 inhibitors and oseltamivir emerged.
T397	172261-172403	Epistemic_statement	denotes	From these patients, it is clear that antiviral therapy failed to control the influenza infection and that novel NA mutations were recognized.
T398	172646-172729	Epistemic_statement	denotes	The mechanisms of resistance to NAIs are complex and require further investigation.
T399	172730-172873	Epistemic_statement	denotes	Future studies should assess the impact of HA mutations and sialyation of HA on the virus dependence on the NA activity and NAI susceptibility.
T400	173274-173470	Epistemic_statement	denotes	The recent events associated with the SARS epidemic and outbreak of influenza A/H7N7 in Europe further emphasize the importance of planning ahead for pandemics and potential biologic catastrophes.
T401	173635-173771	Epistemic_statement	denotes	The development of live-attenuated and recombinant vaccines holds great promise for preventing viral respiratory diseases in the future.

T1

Epistemic_statement

denotes

Interestingly, the Maori had a higher death rate (43.3/1000) than Europeans (7.6/1000), a finding that suggests prior exposure to influenza may have minimized mortality.

T2

2600-2754

Epistemic_statement

denotes

Jeffrey Taubenberger has sequenced the HA, NA, NS, M, and NP genes of the 1918 Spanish influenza virus and found that it is closely related to swine H1N1.

T3

2755-2847

Epistemic_statement

denotes

Unfortunately, the molecular basis of the high pathogenicity of this virus is still unknown.

T4

2848-3079

Epistemic_statement

denotes

Likewise, it is unclear if the virus, the hemagglutinin and neuraminidase genes of which derived 1977-present No from an avian influenza virus, directly infected man and then infected pigs or if pigs served as an intermediate host.

T5

3851-4050

Epistemic_statement

denotes

Acquisition of avian influenza genes by swine influenza viruses has been documented in H1N1 isolates in Europe, H4N6 in Canada, and H9N2 in China, although these latter two instances were transitory.

T6

4051-4252

Epistemic_statement

denotes

In the United States, H3N2 viruses became a problem in pigs in 1998 when the infection was associated with respiratory signs, high fever (104-107 • F), high morbidity (100%), and high risk of abortion.

T7

4339-4560

Epistemic_statement

denotes

Interestingly, analysis of three of the porcine H3N2 viruses revealed that the virus has undergone triple reassortment and had acquired human PB1, HA, and NA genes, porcine NP, M, and NS genes, and avian PA and PB2 genes.

T8

4561-4674

Epistemic_statement

denotes

There is growing evidence, too, that H1N1 swine influenza A viruses are acquiring avian polymerase genes as well.

T9

4675-4903

Epistemic_statement

denotes

Although pigs appear to be an important reservoir and mixing pot for potential human influenza viruses, the chicken H5N1 and H9N2 viruses that have recently emerged in Asia suggest chickens may also be an important intermediary.

T10

5444-5669

Epistemic_statement

denotes

Additional studies of the local chicken market demonstrated that when H5N1 virus infected a chicken it resulted in its death, while chickens co-infected with H9N2 viruses were protected from illness but efficiently shed H5N1.

T11

5670-5869

Epistemic_statement

denotes

The H5N1 virus still appears to be a problem with re-emergence of a different H5N1 virus in 2001; fortunately an outbreak of human infections was prevented by the massive slaughter of chickens again.

T12

6268-6450

Epistemic_statement

denotes

Upon further investigation of these H5N1 outbreaks in chickens and humans, it became clear that quail might play a significant role in interspecies transmission of influenza viruses.

T13

6451-6606

Epistemic_statement

denotes

It appears that quail acquire infection from fecal sources and then replicate virus in their respiratory tract with evidence of tracheal shedding of virus.

T14

6607-6722

Epistemic_statement

denotes

The outbreaks in chickens were associated with the reintroduction of H6N1 and H9N2-infected quail into the markets.

T15

6723-6871

Epistemic_statement

denotes

To address the concerns that quail are intermediates in the transmission of influenza, quail have been banned from all poultry markets in Hong Kong.

T16

7237-7396

Epistemic_statement

denotes

Since the H5N1 virus has caused severe disease in humans already and is a potential pandemic threat, several researchers are looking for its virulence factors.

T17

7693-7851

Epistemic_statement

denotes

Several studies subsequently documented that the NS1 protein of the H5N1 was an antagonist of the antiviral activity of several cytokines (Seo et al., 2002) .

T18

9019-9079

Epistemic_statement

denotes

Unfortunately, powerful technique brings several challenges.

T19

9080-9346

Epistemic_statement

denotes

Since it is so easy to make reassortant viruses, it could be possible to create viruses with several pathogenic genes or viruses that are highly resistant to antivirals resulting in highly transmissible and lethal agents that could be used as agents of bioterrorism.

T20

9347-9487

Epistemic_statement

denotes

In this regard, dangerous constructs need to be contained within BSL3+ level facilities, limiting the number of centers that can study them.

T21

9488-9705

Epistemic_statement

denotes

To prepare for the future, with the current risks of bioterrorism and pandemic influenza, it is essential that surveillance, using global WHO human and animal networks, and yet to be developed biosensors, be expanded.

T22

9706-9907

Epistemic_statement

denotes

Additionally, vaccines and their production need to be studied since it currently takes 6 months to prepare a new vaccine and there may not be a mild warning wave of infection before the next pandemic.

T23

9908-9995

Epistemic_statement

denotes

Lastly, antivirals need to be stockpiled and new antiviral agents need to be developed.

T24

10702-10822

Epistemic_statement

denotes

Although most infections have been documented in children, up to 20% of infections occur in patients over the age of 60.

T25

10823-10983

Epistemic_statement

denotes

Preliminary data suggests that hMPV may be responsible for approximately 7-8% of viral respiratory tract illnesses (RTI) in children and 2-3% of RTIs in adults.

T26

11766-11901

Epistemic_statement

denotes

Sequencing of the N, P, M, F, M2, SH, G, and L genes indicates that hMPV is most closely related to APV (van den Hoogen et al., 2002) .

T27

12041-12157

Epistemic_statement

denotes

There appear to be two genetic and serotypic clusters of hMPV with two subclusters of each cluster (A1, A2, B1, B2).

T28

12158-12364

Epistemic_statement

denotes

(Guy Boivin, Laval University, Québec, Canada) A new paramyxovirus, the human metapneumovirus (hMPV), has been recently isolated from Dutch children with respiratory symptoms (van den Hoogen et al., 2001) .

T29

12365-12484

Epistemic_statement

denotes

However, the prevalence, clinical presentation, and severity of hMPV infections in children have not been well studied.

T30

13571-13767

Epistemic_statement

denotes

hMPV was associated with bronchiolitis in 66.7%, otitis media in 50%, and pneumonia in 16.7% of infected children; no hMPV children were sick enough to require admission to an intensive care unit.

T31

14025-14217

Epistemic_statement

denotes

Dr. Boivin also discussed an outbreak investigation in which there appears to be a nosocomial outbreak of hMPV in a nursing home, giving further information about the impact of this new virus.

T32

14377-14531

Epistemic_statement

denotes

(Robert Couch, Baylor College of Medicine, Houston, TX) Multiple respiratory viruses can be detected sometimes in patients with respiratory tract illness.

T33

14705-14782

Epistemic_statement

denotes

The frequency of dual infection appears to be higher in children than adults.

T34

14783-14868

Epistemic_statement

denotes

The types of diagnostic techniques utilized greatly impacts the detection of viruses.

T35

15801-15871

Epistemic_statement

denotes

The impact of dual infections on disease course has also been studied.

T36

16352-16523

Epistemic_statement

denotes

The exact mechanism for this reduction of viral shedding and symptom severity is not known but transient immunity from the previous infection may contribute to the effect.

T37

17216-17366

Epistemic_statement

denotes

Although not well controlled for in these studies, the timing of infection and the type of viruses likely impact the duration and severity of illness.

T38

17367-17644

Epistemic_statement

denotes

Available information is insufficient for firm conclusions on the illness consequences of dual respiratory viral infections, and future studies should be address the relationships between illness severity and etiology, time course, and quantitative virology of dual infections.

T39

17650-17893

Epistemic_statement

denotes

Respiratory pathogens in the first year of life: a birth cohort study using PCR (Sebastian Johnston, Imperial College London, UK) Numerous studies have documented an association between asthma exacerbations and respiratory viral illness (RVI).

T40

18036-18169

Epistemic_statement

denotes

Several recent studies have expanded on our understanding of the epidemiology of RVIs and their relationship to asthma exacerbations.

T41

19319-19663

Epistemic_statement

denotes

Patients with hRV infections alone were hospitalized earlier in an illness episode (1.8 days versus 3.1 days, P = 0.001) and had a higher likelihood of having a clinical severity score on admission above the 50th percentile (OR 4.9, P = 0.022) after controlling for age, gender, birth weight, presence of fever, and day of disease on admission.

T42

21061-21354

Epistemic_statement

denotes

Among those with URI, 84% had picornaviruses, 11% had RSV, and 5% had dual infections; non-wheezing LRI was associated with picornavirus detection in 74%, RSV in 23%, and dual infection in 3%; wheezing LRI was associated with picornavirus in 70% of cases, RSV in 22%, and dual infection in 8%.

T43

21423-21723

Epistemic_statement

denotes

Although RSV is perhaps more likely to be associated with severe lower respiratory tract illness, these data indicate that rhinoviruses are major respiratory pathogens during the first year of life and cause about three times as many LRIs in the first year of life as RSV in non-hospitalized infants.

T44

21724-21801

Epistemic_statement

denotes

The specific picornavirus that cause these illnesses remain to be identified.

T45

22993-23288

Epistemic_statement

denotes

Among the most prevalent serotypes associated with human respiratory disease, adenovirus type 7 (Ad7) is a frequent cause of severe clinical presentations in children and young adults, in whom it causes epidemics of acute febrile respiratory illness among military recruits (Ryan et al., 2002) .

T46

23289-23454

Epistemic_statement

denotes

Extrapulmonary manifestations, rare fatalities, and residual lung damage are observed in association with Ad7 infection (Becroft, 1967; Steen-Johnsen et al., 1969) .

T47

23455-23628

Epistemic_statement

denotes

Affected patients surviving severe disease may have chronic sequelae in the form of bronchiectasis, bronchiolitis obliterans and hyperlucent lung (Murtagh and Kajon, 1997) .

T48

23966-24146

Epistemic_statement

denotes

The molecular bases of these substitutions of one genome type for another, called genome type "shifts", and the selective forces driving adenovirus evolution in nature are unknown.

T49

24147-24236

Epistemic_statement

denotes

Moreover, the impact of genetic variability on adenovirus virulence is poorly understood.

T50

24551-24876

Epistemic_statement

denotes

Ad7b is still the most prevalent genome type isolated in Europe and North America and Ad7h is still recovered from the nasopharyngeal secretions of children hospitalized for ARI in the South America, observations suggesting an adaptive advantage of their array of genes over the preceding prevalent genome type in the region.

T51

24877-25190

Epistemic_statement

denotes

Interestingly, Ad7h has been recently detected in the United States and Japan in association with respiratory illness and in Brazil in association with acute conjunctivitis, findings that suggest a recent introduction and dissemination of this virus from previously geographically restricted areas of circulation.

T52

25191-25407

Epistemic_statement

denotes

Ad7d 2 , originally reported to circulate in China and later on in Japan and Israel, has been identified in recent outbreaks of ARI in the United States affecting children and military trainees Gerber et al., 2001) .

T53

25633-25743

Epistemic_statement

denotes

These findings suggest that genome type shifts are not strongly determined by selection of antigenic variants.

T54

26113-26340

Epistemic_statement

denotes

However, the implications of genetic variation for human disease are still unclear and will remain elusive until Ad7 genome types are characterized phenotypically and a correlation between genotype and phenotype is established.

T55

26630-26784

Epistemic_statement

denotes

Reverse genetics has been used to create viruses with an influenza A/WSN background, that contain genes from the 1918 strain or more contemporary strains.

T56

26785-26973

Epistemic_statement

denotes

In a recent experiment, conducted in a BSL4 laboratory, three viruses were created: a wild-type WSN virus, a WSN virus with 1918 HA and NA genes, and a WSN virus with 2001 HA and NA genes.

T57

27906-28017

Epistemic_statement

denotes

Such findings indicate that HA and NA of the 1918 virus are linked in part to its virulence in mammalian hosts.

T58

28018-28099

Epistemic_statement

denotes

Protection against the 1918 virus could be achieved by antivirals and antibodies.

T59

28481-28705

Epistemic_statement

denotes

The concept of original antigenic sin, in which humans exposed or vaccinated to influenza will produce higher antibodies against the first virus they were exposed to than against subsequent viruses, may explain this finding.

T60

28706-28852

Epistemic_statement

denotes

In turn, this could partly explain why older patients may have been relatively protected relative to younger individuals during the 1918 pandemic.

T61

28853-28994

Epistemic_statement

denotes

Another question that has recently been answered, although the significance of it is still under investigation, is how the virus is packaged.

T62

29125-29223

Epistemic_statement

denotes

Several studies were then conducted to determine if segment incorporation was random or selective.

T63

29863-29998

Epistemic_statement

denotes

This suggests that, although the NCFBP is required, the coding region, in this case NA, is required for incorporation into new virions.

T64

29999-30149

Epistemic_statement

denotes

Additional studies documented that this virion incorporation signal (VIS), which frequently contained UAU coding regions, was unique for each segment.

T65

30266-30550

Epistemic_statement

denotes

Lastly, the packaging of segments within the virion was assessed through electron microscopy, which demonstrated that there is likely an interaction between base pairs on each of the segments that results in the segments aligning with one another in a fixed way (Fujii et al., 2003) .

T66

30551-30658

Epistemic_statement

denotes

These interactions require greater study as this is a potential target for drugs or vaccines of the future.

T67

30900-31080

Epistemic_statement

denotes

The main challenge in creating a potential live vaccine is to develop a virus that is both highly and stability attenuated while maintaining a satisfactory level of immunogenicity.

T68

31081-31293

Epistemic_statement

denotes

Reverse genetics have be used to achieve this goal by creating an array of potential mutations, fine tuning the level of attenuation, increasing the immunogenicity of the virus, and decreasing its reactogenicity.

T69

31526-31807

Epistemic_statement

denotes

Vaccine candidates for RSV (strain A2 of subgroup A) had previously been developed by conventional biological means, involving passage at suboptimal temperature ("cold passage" [cp]) followed by chemical mutagenesis and the identification of temperature sensitive (ts) derivatives.

T70

32036-32143

Epistemic_statement

denotes

However, it retained the ability to cause mild nasal congestion and thus would require further attenuation.

T71

32407-32577

Epistemic_statement

denotes

This list was expanded by finding that a number of RSV genes, including NS1, NS2, SH and M2-2, could be deleted to yield derivatives that proved to be attenuated in vivo.

T72

32578-32794

Epistemic_statement

denotes

This new knowledge was applied to reverse genetics to create two new viruses, 248/404/ SH and 248/404/1030/ SH, the second of which shows promise in early clinical trials and appears to be free of residual virulence.

T73

32971-33282

Epistemic_statement

denotes

Reverse genetics also can be used to increase gene stability to prevent reversion by incorporating multiple point mutations, by designing amino acid substitutions to involve at least two nucleotide changes compared to assignments yielding wild type or wild type-like phenotypes, and by employing gene deletions.

T74

33283-33468

Epistemic_statement

denotes

Further investigation suggests that moving the G and F genes to a more proximal location in the genome results in increased efficiency of G and F expression and enhanced immunogenicity.

T75

33658-33921

Epistemic_statement

denotes

It might also be possible to reduce the reactogenicity of an RSV vaccine using strategies developed from immunobiological studies: one example would be to ablate the secreted form of G, which has been implicated in preferential sensitization of Th2 T lymphocytes.

T76

34128-34206

Epistemic_statement

denotes

Reverse genetics has also been applied to hPIV3 to develop vaccine candidates.

T77

34207-34325

Epistemic_statement

denotes

A promising hPIV3 vaccine candidate, cp45, had previously been developed by the conventional approach of cold passage.

T78

35402-35502

Epistemic_statement

denotes

This chimeric virus retained the attenuation phenotype and represents a promising vaccine candidate.

T79

35748-35838

Epistemic_statement

denotes

This suggests that a vaccine based on the attenuated bPIV3 backbone should be very stable.

T80

35839-36041

Epistemic_statement

denotes

It also indicated that the introduction of individual bPIV3 genes into hPIV3 is an additional strategy for attenuation, one that is now being pursued with a version of hPIV3 containing the bPIV3 N gene.

T81

36259-36503

Epistemic_statement

denotes

Here, the strategy of "importing" mutations, in particular from RSV and hPIV3, has been particularly useful and has resulted in the development of a number of attenuating mutations that will serve as the basis for live hPIV1 and hPIV2 vaccines.

T82

36504-36634

Epistemic_statement

denotes

Finally, reverse genetics have been used to create attenuated, chimeric virus vectors to protect against multiple paramyxoviruses.

T83

37180-37391

Epistemic_statement

denotes

The availability of PIV vectors expressing RSV antigens offers a novel approach for the immunization or, alternatively, provides an efficient method of "boosting" an initial vaccination made by a live RSV virus.

T84

37392-37707

Epistemic_statement

denotes

It is anticipated that these methods will result in the development of live vaccines against RSV and hPIV3, which preferably would be given in the first weeks of life, and against hPIV1 and hPIV2, which cause disease somewhat later during the first year of life such that vaccination could begin at 6 months of age.

T85

37908-38123

Epistemic_statement

denotes

The current threat of bio-warfare, in addition to availability of anti-influenza drugs for prevention and treatment, makes the rapid identification of these pathogens essential to medical personnel and the military.

T86

38124-38216

Epistemic_statement

denotes

In the battlefield situation, ambient storage and transport of specimens would be desirable.

T87

39829-40082

Epistemic_statement

denotes

Since room temperature storage techniques are easier to accomplish in most locations and since PCR techniques are widely available to the military, the techniques used in this study should expand the ability to provide respiratory pathogen surveillance.

T88

40328-40412

Epistemic_statement

denotes

Unfortunately, the world does not appear to be prepared for a pandemic of influenza.

T89

40752-40875

Epistemic_statement

denotes

Guidelines for vaccines have been developed, but there is widespread concern that vaccine production will lag behind needs.

T90

41383-41517

Epistemic_statement

denotes

Although progress is being made, a pandemic may occur at any time and greater steps need to be taken to minimize its potential impact.

T91

41518-41943

Epistemic_statement

denotes

The United States Department of Health and Human Services has established the Interagency Pandemic Influenza Working Group, with input from the Centers for Disease Control, the Food and Drug Administration, the National Institutes of Health, the Department of Defense, the Office of the General Council, the Office of Planning and Evaluation, the Office of Emergency Preparedness, and the National Vaccine Advisory Committee.

T92

42220-42436

Epistemic_statement

denotes

Several actions have been proposed to strengthen national and global capabilities for virologic and disease surveillance with a view to increasing the likelihood of early detection of viruses with pandemic potential.

T93

44137-44286

Epistemic_statement

denotes

A web-based program, FluAid 2.0 (http://www2.cdc.gov/od/fluaid) has been developed which will help states estimate the potential impact of influenza.

T94

44287-44439

Epistemic_statement

denotes

The third, and perhaps largest objective of the Working Group, is to strengthen influenza-related public health practices, infrastructure, and research.

T95

44772-45028

Epistemic_statement

denotes

Research on influenza biology and epidemiology, animal surveillance, and vaccine and antiviral development has been and will continue to be supported by NIH through grants to academic researchers and through grants that support public-private partnerships.

T96

45029-45215

Epistemic_statement

denotes

Development of cell culture-based vaccines and the testing in humans of candidate pandemic vaccines made using reverse genetics or classical reassortment techniques should be encouraged.

T97

45957-46051

Epistemic_statement

denotes

Such policies will need to take into account liability protection and equitable global access.

T98

46362-46571

Epistemic_statement

denotes

It is essential that policy makers and the public understand the potential threat that influenza poses to mankind so that firm political and financial commitments are made to minimize the impact of a pandemic.

T99

46572-46894

Epistemic_statement

denotes

The best defense against an influenza pandemic is to strengthen the capacity to respond to seasonal epidemics of influenza through improved surveillance, increased vaccine use, enhanced vaccine production, and development of a more effective vaccine delivery infrastructure that could function effectively in an emergency.

T100

46895-47052

Epistemic_statement

denotes

Policy makers should take advantage of and integrate bioterrorism planning with pandemic influenza preparedness and develop flexible, science-based policies.

T101

47150-47269

Epistemic_statement

denotes

Despite the significant progress made in some countries, pandemic influenza planning in Europe is still in its infancy.

T102

48883-49066

Epistemic_statement

denotes

If a monovalent vaccine was used in combination with a potent adjuvant, the required antigen could be potentially reduced to 3.25 g and increase capacity to 12 million doses per week.

T103

49575-49695

Epistemic_statement

denotes

Likewise, there has yet to be a concerted effort to stockpile antiviral agents and supplies of these agents are limited.

T104

50096-50285

Epistemic_statement

denotes

Pandemic plans have been developed in 19 of the 20 European Influenza Surveillance Scheme participating countries, although implementation of the plans has been, for the most part, limited.

T105

50496-50612

Epistemic_statement

denotes

Australia has developed a 'Framework' for an influenza pandemic plan and has begun to implement its recommendations.

T106

50613-50888

Epistemic_statement

denotes

The Influenza Pandemic Planning Committee (IPPC) was chartered to develop a contingency plan and make recommendations for infrastructure and strategies required to minimize the mortality, morbidity, social disruption and economic losses associated with an influenza pandemic.

T107

50889-51173

Epistemic_statement

denotes

The work of the Committee and its recommendations were published as a comprehensive document which incorporated as an appendix the contingency plan for health care institutes prepared for the Victorian state plan: http://www.health.gov.au/pubhlth/strateg/communic/ tech/influenza.htm.

T108

51308-51577

Epistemic_statement

denotes

The major recommendations were the maintenance of an ongoing pandemic planning committee, further impact modeling, adoption of WHO 'alerts', improvement of interpandemic use of vaccine, development of an antiviral stockpile, and development of communication strategies.

T109

51578-51686

Epistemic_statement

denotes

A National Pandemic Action Committee (NIPAC) has recently been formed with the following terms of reference:

T110

51687-51719

Epistemic_statement

denotes

During the interpandemic period:

T111

51720-52162

Epistemic_statement

denotes

• Assisting the Government with development of national policies on vaccination strategies, surveillance and antiviral stockpiling; • Establishing working parties to progress policy issues from the Action Plan; • Collaborating with the States and Territories to prepare their plans; • Revising and promoting the Action Plan in consideration of the changing global agenda; • Regularly reporting progress to the Department of Health and Ageing.

T112

52499-52846

Epistemic_statement

denotes

However, whilst these steps have been taken and pandemic planning has been elevated within the bureaucracy, there has yet to be significant commitment of funds, there has been little regional involvement and, apart from representation through the WHO Collaborating Centre, Australia has not yet contributed greatly to global pandemic preparedness.

T113

53351-53629

Epistemic_statement

denotes

Susceptibility to pandemic influenza will depend on whether the virus is a re-emergent virus similar to one that has infected people in the past, for example influenza A (H2N2), or an entirely new virus like the avian influenza A (H5N1) virus that appeared in Hong Kong in 1997.

T114

53630-53868

Epistemic_statement

denotes

If it is an influenza A (H2N2)-like virus, people over the age of 35 years (approximately 40% of the world's population) are likely to have been immunologically primed by past infection and will require only one 'booster' dose of vaccine.

T115

53869-53973

Epistemic_statement

denotes

If the virus is entirely new, no one will have been primed and everyone will probably require two doses.

T116

53974-54236

Epistemic_statement

denotes

Moreover, because the clinical effectiveness and cost-effectiveness of vaccinating not only older adults but also younger adults and children is widely appreciated, health officials in many countries may choose to vaccinate most, if not all of their populations.

T117

54670-54773

Epistemic_statement

denotes

For this reason, companies make conservative estimates of how much vaccine they will produce each year.

T118

54774-54956

Epistemic_statement

denotes

When demand for vaccine increases suddenly, as it will when a pandemic threat appears, vaccine companies will probably lack the production capacity to respond adequately and quickly.

T119

54957-55138

Epistemic_statement

denotes

Because a pandemic vaccine will probably be monovalent rather than trivalent, it is theoretically possible that the number of doses that might be produced could increase three-fold.

T120

55139-55225

Epistemic_statement

denotes

Nonetheless, pandemic vaccine is still likely to be in short supply in most countries.

T121

55226-55385

Epistemic_statement

denotes

Prudent national health officials may choose to lock in a future supply of pandemic vaccine by negotiating a long-term forward contract with a vaccine company.

T122

55542-55719

Epistemic_statement

denotes

When a pandemic threat appears, within a period of a few months scores of countries will try to negotiate contracts for pandemic vaccine supply with a small number of companies.

T123

55788-55930

Epistemic_statement

denotes

Moreover, they are likely to be compromised by the 'nationalization' of vaccine production in countries that have influenza vaccine companies.

T124

55931-56034

Epistemic_statement

denotes

This is what political leaders in the United States did for Swine influenza vaccine production in 1976.

T125

56035-56179

Epistemic_statement

denotes

Canadian health officials remember this well, which is one reason why they signed their contract with their domestic influenza vaccine producer.

T126

56410-56472

Epistemic_statement

denotes

This new approach must address the following six major issues.

T127

56473-56578

Epistemic_statement

denotes

(1) When a pandemic threat appears, there will be delay in preparing seed strains for vaccine production.

T128

56579-56658

Epistemic_statement

denotes

This might be overcome by using reverse genetics to prepare these seed strains.

T129

56659-56761

Epistemic_statement

denotes

In principle, reverse genetics could be used to prepare high-growth variants for efficient production.

T130

56762-56973

Epistemic_statement

denotes

This may be essential if the pandemic virus is of avian origin because many of these viruses grow poorly (or not at all) in embryonated eggs, the culture system used for all current influenza vaccine production.

T131

56974-57218

Epistemic_statement

denotes

As long as issues regarding the worker safety and the intellectual property rights attached to reverse genetics can be sorted out beforehand, this promising technique could be the key factor for ensuring adequate production of pandemic vaccine.

T132

57219-57301

Epistemic_statement

denotes

(2) Whether the pandemic threat is due to a re-emergent (A/H2-like) or novel (e.g.

T133

57302-57438

Epistemic_statement

denotes

A/H5-like) virus will determine not only the kind of vaccine that should be produced but also whether one or two doses will be required.

T134

57550-57710

Epistemic_statement

denotes

Studies conducted many years ago indicated that whole cell vaccines were more immunogenic than split virus or subunit preparations of similar antigenic content.

T135

57711-57839

Epistemic_statement

denotes

Moreover, recent studies have shown that an adjuvanted vaccine will probably be needed for at least the first if not both doses.

T136

57840-57950

Epistemic_statement

denotes

These studies need to be extended in a larger series of clinical trials of candidate 'pandemic-like' vaccines.

T137

58174-58302

Epistemic_statement

denotes

In Western Europe, immunogenicity studies must be undertaken by vaccine companies each year in order to register their products.

T138

58501-58571

Epistemic_statement

denotes

For the next pandemic, such trade is likely to be much more extensive.

T139

58572-58815

Epistemic_statement

denotes

If pandemic vaccines are to be delivered quickly to the countries where they are needed most, a global protocol will be required that will allow the pandemic vaccine produced by any company to be registered for use in any country of the world.

T140

58816-58950

Epistemic_statement

denotes

The need for a protocol for the global registration of pandemic vaccines should be considered before the next pandemic threat appears.

T141

58951-59087

Epistemic_statement

denotes

(4) Countries will be better prepared for the next pandemic if they can increase their use of influenza vaccine in inter-pandemic years.

T142

59088-59243

Epistemic_statement

denotes

This was started by the Canadian province of Ontario in 2000, when it extended its recommendation for influenza vaccine to all people over 6 months in age.

T143

59326-59533

Epistemic_statement

denotes

Health officials can help prepare for the next pandemic by expanding their influenza vaccination recommendations and extending their programs for public reimbursement for vaccination in inter-pandemic years.

T144

59671-59844

Epistemic_statement

denotes

Although many vaccine companies are expanding their production facilities, it is still difficult for them to estimate future demand for inter-pandemic and pandemic vaccines.

T145

59982-60420

Epistemic_statement

denotes

One way to overcome uncertainty about future demand for influenza vaccines would be to: (a) obtain country-specific data on the number of doses of influenza vaccine distributed each year by each vaccine company and rapidly report the total number of doses distributed per 1000 population in all countries; and (b) obtain 5-year rolling forecasts of the demand for inter-pandemic and pandemic vaccine from health officials in each country.

T146

60421-60633

Epistemic_statement

denotes

The availability of such past and future information would challenge health officials to make more comprehensive plans for vaccination programs and help companies make more realistic plans for vaccine production.

T147

60634-60845

Epistemic_statement

denotes

(6) Political leaders in most vaccine-producing countries will probably prohibit the export of domestically produced pandemic vaccine to other countries until they are certain their national needs have been met.

T148

60846-61064

Epistemic_statement

denotes

As a result, countries that do not have vaccine companies, including many that currently use large amounts of vaccine in inter-pandemic years, may find it difficult or impossible to obtain supplies of pandemic vaccine.

T149

61411-61560

Epistemic_statement

denotes

Effective planning for pandemic influenza and the global vaccine supply will require the skills of experts in virology, epidemiology and vaccination.

T150

61561-61650

Epistemic_statement

denotes

Equally important, however, will be the skills of experts in politics, economics and law.

T151

61651-61727

Epistemic_statement

denotes

Coordinating their efforts at an international level will be very difficult.

T152

61901-61948

Epistemic_statement

denotes

How good are the rapid diagnostic tests really?

T153

61949-62509

Epistemic_statement

denotes

(Peter Wright, Vanderbilt University Medical Center, Nashville, TN and Ruth Karron, Johns Hopkins University, Baltimore, MD) Rapid diagnostic tests for respiratory viral illness has become an increasingly important tool because of the advent of effective antiviral agents that are maximally effective if started early in the course of the illness, the need to isolate patients who could pass their infection to other ill patients, and the need to differentiate between these viral illnesses and other respiratory tract pathogens, including bioterrorism agents.

T154

62510-62574

Epistemic_statement

denotes

However, currently available rapid testing has many limitations.

T155

62575-62952

Epistemic_statement

denotes

Areas of improvement that need to be addressed include the ability to test for all or most know agents, improved collection methods, improved integration of diagnosis with use of medications and clinical care, use of diagnostics for epidemiology and vaccine development, increased sensitivity in adults and immunocompromised patients, and improved ease and accuracy of testing.

T156

63029-63263

Epistemic_statement

denotes

There are significant limitations of these tests including sensitivities and specificities that are dependent on the quality of the sample collected, the timing of the illness, the intensity of the epidemic, and the population tested.

T157

63264-63437

Epistemic_statement

denotes

These assays have been developed to allow for sentinel surveillance, although their positive predictive values are limited at the beginning and end of epidemics (see below).

T158

63438-63614

Epistemic_statement

denotes

In addition, rapid testing helps to identify patients who may benefit from antiviral agents and to decrease the use of antibiotics and shorten the duration of hospitalizations.

T159

65071-65309

Epistemic_statement

denotes

Unfortunately, reported sensitivities and specificities of these various tests cannot be directly compared, since different 'gold standards', source populations, sample types (fresh versus frozen; nasal versus throat), and operators (i.e.

T160

65415-65723

Epistemic_statement

denotes

Use of a particular rapid diagnostic test for influenza should be determined according to the level of identification needed (influenza A or B versus influenza A and B), price, CLIA status, specimen type, staff familiarity with methods, turn-around-time, and relative sensitivity and specificity of the test.

T161

65797-66016

Epistemic_statement

denotes

For example, if the sensitivity and specificity of the test was 80%, and the prevalence of influenza was 5%, the positive predictive value (PPV) of the test would be 17%; if the prevalence was 20%, the PPV would be 50%.

T162

66136-66262

Epistemic_statement

denotes

When clinically important (for example, in hospitalized patients), negative rapid test results should be confirmed by culture.

T163

67838-68179

Epistemic_statement

denotes

Three types of mice can be used for such experiments: transgenic mice, where the gene encoding the molecule of interest is over-expressed or expressed in an abnormal location (tissue), knock-out mice, which have specific genes or gene segments deleted, and knock-in mice, which have mutated forms of the gene replacing the wild-type version.

T164

68481-68568

Epistemic_statement

denotes

These studies suggest that collectins regulate the innate and adaptive immune response.

T165

69483-69655

Epistemic_statement

denotes

Interferon may limit influenza virus dissemination for those strains that can replicate outside of the respiratory tract, a process that is more difficult to model in mice.

T166

70260-70397

Epistemic_statement

denotes

Recovery from infection can be mediated by the remaining adaptive immune response in conjunction with the ongoing innate immune response.

T167

70398-70531

Epistemic_statement

denotes

Ex-periments with these mice suggest that resistance to repeat infection and hetero-subtypic immunity is mediated in part by B cells.

T168

70532-70633

Epistemic_statement

denotes

The role of secretory antibodies has been studied using IgA, J chain, and poly-Ig receptor knockouts.

T169

70634-70875

Epistemic_statement

denotes

These studies have demonstrated that secretory IgA is not required for recovery from pulmonary infection but that secretory IgA may enhance clearance of homotypic and heterosubtypic virus from the upper respiratory tract following infection.

T170

71765-71854

Epistemic_statement

denotes

Immunologic memory in the respiratory tract may not be accurately reflected systemically.

T171

71855-72041

Epistemic_statement

denotes

With greater understanding of the innate and adaptive immune response, it may be possible to develop vaccines with improved efficacy or with the ability to modulate the pulmonary injury.

T172

72163-72269

Epistemic_statement

denotes

It is not known why some infected infants develop severe disease, whereas the majority have mild symptoms.

T173

72270-72439

Epistemic_statement

denotes

In response to infection, the host produces a complex mixture of cytokines and other inflammatory mediators with anti-viral but also potentially pathological properties.

T174

72440-72701

Epistemic_statement

denotes

Various clinical and experimental observations indicate that certain patterns of host response are associated with severe disease, but it has been extremely difficult to prove that these are causal determinants, rather than just correlates, of clinical outcome.

T175

72702-72854

Epistemic_statement

denotes

To better understand the association between clinical response to infection (phenotype) and specific genes, genetic association studies need to be done.

T176

72855-72944

Epistemic_statement

denotes

Genetic association studies can be done using a genome approach or using candidate genes.

T177

72945-73121

Epistemic_statement

denotes

It has been estimated that genomic approaches would require study of at least 200,000 markers in several thousand subjects, a project which would cost many millions of dollars.

T178

73189-73371

Epistemic_statement

denotes

Several candidate genes have been identified that may play a role in the immune response to RSV, including IL-5, 8, 10, and 13, CCR5, ICAM-1, IL-4 receptor, IFN-␥ and IFN-␥ receptor.

T179

73372-73565

Epistemic_statement

denotes

The primary objective of current genetic association studies is to identify host factors that contribute to the development of severe lower respiratory tract disease following infection by RSV.

T180

73566-73808

Epistemic_statement

denotes

These studies will address this problem through a molecular genetic approach, by investigating whether disease susceptibility is related to common polymorphisms in host genes that are thought to be critical for protection and/or pathogenesis.

T181

74194-74302

Epistemic_statement

denotes

We have previously demonstrated that IL-8 promoter polymorphisms may influence the level of gene expression.

T182

74303-74352

Epistemic_statement

denotes

IL8-251A is associated with severe bronchiolitis.

T183

74883-75125

Epistemic_statement

denotes

Our current work is directed at fine mapping of the IL8 bronchiolitis susceptibility effect; preliminary studies suggest there is also a link with a RAS effector gene (RASSF6) (OR 2.1) that is located just downstream from the IL-8 gene locus.

T184

75170-75318

Epistemic_statement

denotes

CCR5 is the major receptor for RANTES, MIP-1␣, and MIP-1␤ and has several polymorphisms that are associated with levels of CCR5 on the cell surface.

T185

75319-75394

Epistemic_statement

denotes

Certain polymorphisms of CCR5 have been associated with progression of HIV.

T186

75395-75567

Epistemic_statement

denotes

We have found that a CCR5 promoter SNP (single nucleotide polymorphism; CCR5-2459) is associated with more severe bronchiolitis (OR 1.5; OR 1.8 without other risk factors).

T187

75568-75761

Epistemic_statement

denotes

In combination, the studies on IL8 and CCR5 suggest that the innate immune response of the airway epithelial cells to infection with RSV appears to be important in determining disease severity.

T188

75762-75940

Epistemic_statement

denotes

Another area of interest in RSV pathogenesis relates to chromosome 5q31-33, which contains several markers that have been associated with atopy, IgE levels, and wheezing illness.

T189

76014-76159

Epistemic_statement

denotes

We have found that a common haplotype of IL-4, which 77% of humans carry, is associated with increased risk of severe RSV bronchiolitis (OR 1.5).

T190

76160-76398

Epistemic_statement

denotes

In a Korean study of 105 children under 24 months old with RSV lower respiratory tract infections and 315 blood donors, a different haplotype at IL-4 was also found to be associated with more severe disease (OR 1.63) (Choi et al., 2002) .

T191

76399-76566

Epistemic_statement

denotes

These results suggest that there may be a functional variant at this locus (identified by different haplotypes in different populations) that affects disease severity.

T192

76567-76749

Epistemic_statement

denotes

In addition, we have preliminary data that suggests that a rare haplotype of IL-13, found in only 5% of humans, also affects the risk of bronchiolitis after exposure to RSV (OR 2.0).

T193

76750-76916

Epistemic_statement

denotes

In conclusion, data from genetic association studies indicate that both innate and adaptive immune responses are important in determining the severity of RSV disease.

T194

76917-77112

Epistemic_statement

denotes

Genetic association studies should shed light on the pathogenesis of severe RSV disease, as well as providing information that may allow targeting of therapies to infants at especially high risk.

T195

77113-77286

Epistemic_statement

denotes

This approach could be extended to other common respiratory viral infections, such as those due to influenza and rhinovirus, to understand differences in disease expression.

T196

77962-78275

Epistemic_statement

denotes

These cells are grown on a support in culture and, upon the establishment of an air-liquid interface, differentiate into a multi-layered, pseudostratified, polarized tissue that closely resembles the airway epithelium in vivo with regard to morphology and functions, including mucus production and ciliary motion.

T197

78276-78333

Epistemic_statement

denotes

The cilia are limited to the apical surface of the cells.

T198

78334-78423

Epistemic_statement

denotes

Keratan sulfate is frequently present on ciliated cells and can detected immunologically.

T199

78424-78612

Epistemic_statement

denotes

Wild type recombinant RSV was genetically engineered to express the green fluorescent protein (rgRSV) from an added gene, so that infection could be monitored in real time in living cells.

T200

78613-78714

Epistemic_statement

denotes

rgRSV could only infect the cells when applied to the apical surface and not the basolateral surface.

T201

78806-79012

Epistemic_statement

denotes

Mechanical damage to the tissue, which exposes underlying layers of cells, did not increase the range of infection, indicating that this reflected an authentic tropism rather than simple physical exclusion.

T202

79702-79910

Epistemic_statement

denotes

Thirty-six days after rgRSV infection, intact infected cells were readily detected but, interestingly, cytopathologic effect was minimal, although cells were noted to become rounder in the vertical dimension.

T203

80023-80144

Epistemic_statement

denotes

RSV infection has minimal cytopathic effect with an absence of syncytia, likely due to polarized expression of F protein.

T204

80211-80290

Epistemic_statement

denotes

Like RSV, HPIV3 appears to infect, bud, and spread via the apical surface only.

T205

80291-80447

Epistemic_statement

denotes

HPIV3 also appeared to infect only ciliated cells, and appeared to infect keratin sulfate-containing cells, as well as a subset that lacked keratin sulfate.

T206

80548-80636

Epistemic_statement

denotes

Infection appeared to be completely dependent on sialic acid on the apical cell surface.

T207

80777-80934

Epistemic_statement

denotes

These model systems may help identify cellular receptors for RSV and HPIV3 and should be useful in studying the epithelial cell response to these infections.

T208

81029-81180

Epistemic_statement

denotes

Nosocomial S. aureus outbreaks have been linked to healthcare workers such that concern has been raised that S. aureus could be spread through the air.

T209

81181-81378

Epistemic_statement

denotes

Increased risk of S. aureus airborne transmission has been associated with increased S. aureus in the nose, male sex, snorting or sneezing, antibiotic use, cutaneous diseases, and viral infections.

T210

81733-81882

Epistemic_statement

denotes

The concept was expanded to include adults when an outbreak of S. aureus infections occurred in two newborn nurseries associated with a single nurse.

T211

81883-82098

Epistemic_statement

denotes

During the outbreak investigation, it was noted that the likelihood of this nurse transmitting S. aureus increased five-fold during periods of time when she had an upper respiratory infection (Belani et al., 1986) .

T212

82099-82251

Epistemic_statement

denotes

The possibility that "cloud adults" exist was substantiated during an investigation of another point-source outbreak of S. aureus nosocomial pneumonias.

T213

82530-82710

Epistemic_statement

denotes

Following rhinovirus infection, there was a 40-fold increase in airborne dispersal of S. aureus and this increase could be decreased 75% by wearing a mask (Sherertz et al., 1996) .

T214

83390-83589

Epistemic_statement

denotes

Masks did not blunt this effect but wearing barrier garb (gown, gloves, booties, cap) did, suggesting that in most volunteers the airborne dispersal is not coming in real time directly from the nose.

T215

83906-84103

Epistemic_statement

denotes

Recent studies have shown that coagulase-negative Staphylococci have increased airborne dispersal after a rhinovirus infection suggesting that the "cloud phenomenon" may occur with other organisms.

T216

84104-84379

Epistemic_statement

denotes

This finding may be quite important as it suggests a possible mechanism for the outbreaks of meningococcal, pneumococcal, and streptococcal (Group A) infection that occur in the community and in semi-closed populations as an aftermath to outbreaks of influenza and viral URI.

T217

84380-84674

Epistemic_statement

denotes

One potential hypothesis to explain the pathogenesis of the "cloud adult" is that infection results in inflammation that in turn reduces the diameter of the nasal passage and increases the rate of airflow and associated aerosolization of particulates, including bacteria, by the venturi effect.

T218

84675-84832

Epistemic_statement

denotes

To test this hypothesis, volunteers with allergic rhinitis who had their medication held but did not have culturable virus were placed into the test chamber.

T219

84920-85040

Epistemic_statement

denotes

The inflammatory response in the nose, not the rhinovirus itself, may be central to the mechanism of airborne dispersal.

T220

85041-85246

Epistemic_statement

denotes

Imperial College, London, UK) RSV bronchiolitis in infancy is strongly associated with the later development of asthma (Stein et al., 1999) and RSV is also implicated in virus induced asthma exacerbations.

T221

85477-85621

Epistemic_statement

denotes

Recent evidence suggests that virus-induced asthma exacerbations may be associated with deficient type 1 immunity (Papadopoulos et al., 2002d) .

T222

86359-86515

Epistemic_statement

denotes

We hypothesized that in a type 2 cytokine rich environment (as occurs in asthmatic airways), virus-induced production of type 1 cytokines is down-regulated.

T223

86516-86652

Epistemic_statement

denotes

To test this hypothesis, we studied RSV-induced production of IL-15 in respiratory epithelial cells in the absence and presence of IL-4.

T224

87002-87241

Epistemic_statement

denotes

Decreased production of IL-15 in the lung in respiratory viral infections in asthmatic subjects may be a possible pathway for deficient antiviral immune responses, delayed virus eradication and virus-induced exacerbations of atopic asthma.

T225

87981-88375

Epistemic_statement

denotes

Wheezing can be classified into four types, predominating at distinct ages: transient infant wheeze (likely related to exposure to smoke or small lungs); early wheeze (typically after a viral illness); classical atopic asthma (which tends to be familial) and chronic obstructive airway disease (typically resulting from chronic irritant exposure, such as smoke, throughout a person's lifetime).

T226

88895-89029

Epistemic_statement

denotes

As a result of this significant burden, many have studied asthma and its relationship to respiratory viral diseases, particularly RSV.

T227

90039-90370

Epistemic_statement

denotes

To further investigate a potential link between RSV bronchiolitis and asthma, Wenzel and colleagues conducted a long-term follow-up study of 13 children with bronchopulmonary dysplasia (PBD) who were treated with RSV polyclonal immunoglobulin (RSV-Ig) during infancy and 26 age-matched controls with BPD who did not receive RSV-Ig.

T228

90519-90782

Epistemic_statement

denotes

However, 7-10 years after enrollment, RSV-Ig treated children had significantly better FEV1/FVC ratios and airway conductance, in addition to less atopy, missed school, colds, asthma attacks, hospitalizations, and use of asthma medications (Wenzel et al., 2002) .

T229

90783-91008

Epistemic_statement

denotes

These results raised the question of whether normal lungs become asthmatic after viral infection or if weakened lungs that would become asthmatic without infection are also at increased risk of wheezing after viral infection.

T230

91878-92065

Epistemic_statement

denotes

Taken together, these results suggest that mild infection results in low level IFN-␥ production, while bronchiolitis results in increased IL-4 production in addition (Pala et al., 2002) .

T231

92066-92146

Epistemic_statement

denotes

The age of acquisition of RSV infection may impact on future asthmatic sequelae.

T232

92460-92663

Epistemic_statement

denotes

Such immune maturation hypotheses have been documented by stimulating tonsil extracts from children with RSV and PHA in vitro; these stimulations result in increasing levels of IFN-␥ with increasing age.

T233

92664-92929

Epistemic_statement

denotes

When mice are infected with RSV at 1 day, 1, 4, and 8 weeks of age and then reinfected at 12 weeks of age, infection of older mice resulted in increased viral load, likely secondary to larger lungs with more cells to infect, but similar rates of clearance of virus.

T234

93398-93505

Epistemic_statement

denotes

This data suggests that the nature of the secondary response is determined by the age at primary infection.

T235

93506-93669

Epistemic_statement

denotes

RSV infection early in life sensitizes for severe response to viral challenge later in life and T-cell priming in the neonatal period may explain this association.

T236

93670-93820

Epistemic_statement

denotes

Delaying RSV infection beyond infancy could have long-term benefits in terms of less severe disease, decreased atopy, and lower frequencies of asthma.

T237

93821-94062

Epistemic_statement

denotes

Potential mechanisms for this delayed effect include chronic, persistent, or latent viral infection, remodeling of the lung after infection, permanent epithelial damage, immunologic priming or tolerance, or bystander antigenic sensitization.

T238

94063-94134

Epistemic_statement

denotes

Further studies will need to be done to investigate these alternatives.

T239

94135-94322

Epistemic_statement

denotes

Several studies suggest that some infections in infancy protect against asthma and allergic disease while lower respiratory tract viral illness are associated with wheezing later in life.

T240

94323-94558

Epistemic_statement

denotes

In general infections induce type 1 responses (IFN-␣, IL-12, IL-15, IL-18, IFN-␥) while allergic disorders are associated with type 2 responses (IL-4, IL-5, IL-9, and IL-13); type 1 and type 2 responses are mutually counter-regulatory.

T241

94559-94769

Epistemic_statement

denotes

Immune responses at birth are skewed toward type 2, and microbial exposure is required to develop type 1 responses, so environmental exposure early in life likely contributes to maturation of the immune system.

T242

94969-95114

Epistemic_statement

denotes

Likewise, hepatitis A, likely a marker of load of infectious exposure, is associated with decreased risk of allergies (Matricardi et al., 2002) .

T243

95115-95233

Epistemic_statement

denotes

Respiratory virus infections have been associated with an increased risk of wheezing illness and atopic sensitization.

T244

95787-95966

Epistemic_statement

denotes

However, lower respiratory tract illnesses resulting from other virus types were also significantly associated with increased risk of wheezing later in life (Stein et al., 1999) .

T245

96093-96416

Epistemic_statement

denotes

Potential explanations for the relationship of early virus-related lower respiratory illness including RSV bronchiolitis is that patients with lower respiratory illness/bronchiolitis may have smaller airways, deficient type 1 or increased type 2 immunity, or develop increased allergen sensitization during acute infection.

T246

96417-96665

Epistemic_statement

denotes

To evaluate these potential explanations, Legg and associates collected nasal lavages on days 1, 2 and 5-7 of illness and peripheral blood mononuclear cells on days 5-7 of illness from children in their first year of life with proven RSV infection.

T247

97019-97187

Epistemic_statement

denotes

From these results, the authors concluded that RSV bronchiolitis is associated with deficient type 1 immunity and impaired virus clearance (Mallia and Johnston, 2002) .

T248

97653-97934

Epistemic_statement

denotes

In conclusion, it appears that the risk of allergic disease later in life can be reduced by high overall load of infectious disease (including respiratory viral infections) early in life, but exposure to respiratory infections early in life causes increased morbidity at that time.

T249

97935-98202

Epistemic_statement

denotes

Likewise, individual infections in subjects at risk, such as those with deficient type 1 immunity or small airways, result in infections that are more severe, more likely to involve the lower respiratory tract, and are strongly associated with wheezing later in life.

T250

98379-98529

Epistemic_statement

denotes

Serious illness due to respiratory viruses appears most common in hematopoietic stem cell transplant (HSCT) recipients and lung transplant recipients.

T251

99055-99219

Epistemic_statement

denotes

Our retrospective review found that respiratory viral pneumonia was associated with an increased risk of death (HR 2.2 for RSV, 3.4 for PIV, and 2.4 for influenza).

T252

99354-99490

Epistemic_statement

denotes

This finding suggests that the clinical effects of RVIs are likely both from direct lytic effects and indirect immunomodulatory effects.

T253

99743-100013

Epistemic_statement

denotes

Season, male sex, and transplant type were associated with increased risk of developing RSV infection; unrelated donor status was associated with PIV infection; and season, female sex, and underlying malignancy were associated with increased risk of influenza infection.

T254

100014-100164

Epistemic_statement

denotes

Data from other studies suggest that CD4 lymphopenia also enhances the risk of acquisition of a respiratory viral illness in a dose-dependent fashion.

T255

100165-100266

Epistemic_statement

denotes

Lymphopenia is also associated with increased risk of progression to lower respiratory tract disease.

T256

100692-100806

Epistemic_statement

denotes

Unfortunately, it is not yet possible to determine accurately which patients will progress to lower tract disease.

T257

101771-102116

Epistemic_statement

denotes

Better results have been documented with aerosolized ribavirin alone (22-66% survival) (Harrington et al., 1992; Ljungman et al., 2001) , or in combination with IVIG (50-68% survival) (Ghosh et al., 2001; Ljungman et al., 2001; Whimbey et al., 1995) , RSV-Ig (86-91% survival) (DeVincenzo et al., 2000; Small et al., 2002) or palivizumab (83%) .

T258

102117-102254

Epistemic_statement

denotes

These data suggest that optimal therapy for RSV pneumonia involves the combination of aerosolized ribavirin plus an antibody preparation.

T259

102470-102734

Epistemic_statement

denotes

Potential risk factors for increased mortality in patients with RSV pneumonia includes the co-pathogens, concomitant immunosuppression (steroids, anti-lymphocyte antibodies), lymphopenia, preexisting lung disease, and the therapy used, including the time of onset.

T260

102735-102814

Epistemic_statement

denotes

Prevention strategies should be explored to limit the frequency of RSV disease.

T261

102954-103152

Epistemic_statement

denotes

Use of RSV-Ig or palivizumab for prophylaxis might be beneficial, although the two preparations have never been studied in this population in a randomized fashion and would be very expensive to use.

T262

103153-103373

Epistemic_statement

denotes

Preemptive therapy, with aerosolized ribavirin, could be used in patients with asymptomatic shedding or RSV URIs, although early detection methods limit the ability to implement preemptive management of these infections.

T263

103374-103466

Epistemic_statement

denotes

Additionally, these preemptive strategies have not been tested for RSV in randomized trials.

T264

103467-103622

Epistemic_statement

denotes

As a result of the potentially devastating outcome of RSV and other RVIs, there has been some concern about the need to delay HSCT in symptomatic patients.

T265

104821-104933

Epistemic_statement

denotes

Thus, delay of transplant for at least 1 month should be advised for all myeloablative transplants (CDC, 2000) .

T266

106484-106657

Epistemic_statement

denotes

This study prospectively confirmed that RSV occurs typically in the winter months, can be nosocomially transmitted, and can frequently progress to involve the lower airways.

T267

106734-106870

Epistemic_statement

denotes

RSV infection was associated with a low mortality in this heterogeneous population, despite 33% having lower respiratory tract symptoms.

T268

107942-108159

Epistemic_statement

denotes

A potential causative viral agent was found in 88.7% of cases: RSV 27%, entero-25%, rhino-22%, nontypable picorna-16.4%, adenovirus 5%, hMPV 4%, parainfluenza type 1/3 5%, influenza A and B both 1% and coronavirus 1%.

T269

108488-108587

Epistemic_statement

denotes

RVIs were associated with almost all episodes of wheezing leading to hospitalization in this study.

T270

108588-108791

Epistemic_statement

denotes

This study was also one of the first to demonstrate the contribution of hMPV, particularly during winter epidemics, and its correlation with wheezing (Jartti et al., 2002b; van den Hoogen et al., 2001) .

T271

109868-110006

Epistemic_statement

denotes

The avian influenza H5N1, H9N2, H5N2, H7, and H6 subtypes have recently been identified as high priority for pandemic vaccine development.

T272

111223-111268

Epistemic_statement

denotes

Early studies of this candidate are on-going.

T273

111599-111729

Epistemic_statement

denotes

It is hoped that these and future studies will allow the development of seed lots of vaccine viruses for a range of avian viruses.

T274

111730-111895

Epistemic_statement

denotes

Additionally, alternative substrates for vaccine production and new adjuvants will need to be tested to enhance our armamentarium against pandemic influenza strains.

T275

113139-113352

Epistemic_statement

denotes

From the interim analysis of the first year's data, it appears that CAIV-T confers substantial efficacy against culture-confirmed influenza in Asian children, despite regional differences in influenza circulation.

T276

113353-113457

Epistemic_statement

denotes

Additional data about the impact on AOM and the results of the second year of the study are in progress.

T277

113710-113818

Epistemic_statement

denotes

Approval of the CAIV-T vaccine was slow because of concerns about safety and efficacy in certain age groups.

T278

113819-114012

Epistemic_statement

denotes

The vaccine has been shown to be genetically stable; viruses that have lost their temperature sensitivity or cold-adaptation RNA Virus Virosome have not been recovered from vaccinated patients.

T279

114013-114208

Epistemic_statement

denotes

Likewise, transmission of the vaccine virus is very infrequent; only one case has been documented in which a child in a day care setting acquired the vaccine strain from another vaccinated child.

T280

114318-114507

Epistemic_statement

denotes

The two major concerns on the part of the FDA after their initial advisory panel review in 2001 related to the questions of increased risk of pneumonia and asthma in vaccinated individuals.

T281

115180-115381

Epistemic_statement

denotes

The FDA advisory committee felt that there was adequate data on the efficacy and safety of the vaccine in children >59 months of age and adults younger than 50 to recommend approval for this age group.

T282

115382-115553

Epistemic_statement

denotes

As a result, further studies are needed in the age groups that have not been as completely studied, including young children and otherwise healthy adults aged 50-64 years.

T283

115554-115708

Epistemic_statement

denotes

Virosomes are functionally reconstituted, non-infectious viral envelopes retaining the cell entry properties of the native virus but lacking the RNA core.

T284

116352-116559

Epistemic_statement

denotes

Antigens may also be encapsulated within the lumen of the virosome, so that delivery of the antigen occurs intracellularly and the immune system can react against both the antigen within and on the virosome.

T285

116560-116871

Epistemic_statement

denotes

Theoretically, once taken up by an antigen presenting cell (APC), the virosome would fuse from within the acidic endosomal cell compartment, resulting in delivery of virosome-encapsulated antigen to the cell cytosol, while surface-associated antigen-including part of the HA-would remain behind in the endosome.

T286

116872-116934

Epistemic_statement

denotes

In the cytosol, the antigen would be processed by proteasomes.

T287

116935-117114

Epistemic_statement

denotes

Peptides produced would bind in the ER to MHC class I molecules to be ultimately presented on the APC surface, priming CD8 + T cells to mature into cytotoxic T lymphocytes (CTLs).

T288

117115-117263

Epistemic_statement

denotes

Within the endosome, virosomal antigen would be degraded to allow peptides to bind to MHC class II molecules and activate CD4 + T helper cells (Fig.

T289

118204-118488

Epistemic_statement

denotes

Despite a concern that pre-existing antibodies against HA would block virosome-mediated CTL priming, mice with a high pre-existing antibody titer against virosomal HA developed a strong ovalbumin-specific CTL response after subsequent immunization with ovalbumin-containing virosomes.

T290

118489-118608

Epistemic_statement

denotes

It appears that antibody-opsonized virosomes are actively processed by dendritic cells through uptake via Fc receptors.

T291

119056-119211

Epistemic_statement

denotes

As a result of their broad activation of the immune system and their ability to carry antigens, virosomes hold significant promise for vaccine development.

T292

119212-119372

Epistemic_statement

denotes

Virosomes could also be used as a platform for inclusion of immunomodulators or adjuvants to be used as potential intranasal and/or pandemic influenza vaccines.

T293

119373-119538

Epistemic_statement

denotes

Newer influenza virosome vaccines could be supplemented with other influenza antigens, such as the NP, M1, or M2, for further induction of humoral and CTL responses.

T294

119539-119652

Epistemic_statement

denotes

Potential other applications include vaccine development for bioterrorism agents and therapeutic cancer vaccines.

T295

119894-119988

Epistemic_statement

denotes

Fifteen clinical studies with 2970 patients have been done on the vaccine, called Influvac ® .

T296

119989-120087

Epistemic_statement

denotes

The vaccine has been well tolerated and is at least as effective as conventional subunit vaccines.

T297

120245-120470

Epistemic_statement

denotes

FluINsure TM is a trivalent, subunit influenza vaccine for intranasal inoculation that is composed of inactivated, partially-purified influenza antigens in non-covalent complex with the Proteosome TM adjuvant/delivery system.

T298

120769-120977

Epistemic_statement

denotes

The process has been shown adaptable to egg-grown, detergent-split antigens inactivated by either formalin or ␤-propiolactone, and can also be used with recombinant antigens generated in a baculovirus system.

T299

121173-121319

Epistemic_statement

denotes

Although initially formulated with thimerosal, a preservative-free, 0.22 m filterable product packaged in a unit dose device is under development.

T300

121637-121765

Epistemic_statement

denotes

While intranasal influenza antigens alone may induce some secretory responses, FluINsure TM is 1-2 orders of magnitude superior.

T301

121766-121894

Epistemic_statement

denotes

In addition, FluINsure TM is associated with IgG1: IgG2a ratios suggestive of a Th1-shifted response similar to virus infection.

T302

121895-122149

Epistemic_statement

denotes

This correlates with the observation that spleen cells of animals immunized with nasal FluINsure TM produce the same amount of IFN-␥ as those of animals immunized with IM vaccine when restimulated with virus in vitro, but much less IL-5 (a Th2 cytokine).

T303

122150-122413

Epistemic_statement

denotes

FluINsure TM can protect mice against a lethal respiratory challenge with mouse-adapted homologous virus in a manner indistinguishable from IM vaccine, and also protects ferrets against fever and/or virus shedding following challenge with recent epidemic strains.

T304

122704-122807

Epistemic_statement

denotes

Monovalent prototype and trivalent data are highly consistent regarding both immunogenicity and safety.

T305

123806-124017

Epistemic_statement

denotes

Overall, immune responses to influenza A/H1N1 and A/H3N2 antigens have been quite consistent across multiple studies and lots, whereas responses to B antigens (as with many influenza vaccines) are more variable.

T306

124018-124196

Epistemic_statement

denotes

In trivalent studies performed to date, potentially protective immune responses have been seen in 70-80% for A/H1N1 strains, 70-90% for A/H3N2 strains, and 40-100% for B strains.

T307

124197-124359

Epistemic_statement

denotes

In summary, the FluINsure TM proteosome intranasal influenza vaccine appears to be a promising candidate as it is inexpensive and easily adaptable to new viruses.

T308

124360-124420

Epistemic_statement

denotes

It appears to be safe and immunogenic in animals and humans.

T309

124742-124925

Epistemic_statement

denotes

Studies in adults have demonstrated that the Inflexal V is equal to conventional inactivated influenza vaccine (Fluarix) in terms of immunogenicity and appears to be better tolerated.

T310

125326-125555

Epistemic_statement

denotes

Finally, a non-virosomal intranasal influenza vaccine that used Escherichia coli heat-labile toxin as an adjuvant, previously manufactured by Berna, was removed from the market because of a possible association with Bell's Palsy.

T311

125771-125861

Epistemic_statement

denotes

Although the incidence was low, the company decided to remove the product from the market.

T312

126096-126214

Epistemic_statement

denotes

Preliminary studies of the immunogenicity and tolerability have been undertaken in 40 healthy adults aged 18-45 years.

T313

126685-126838

Epistemic_statement

denotes

This study showed that the vaccine was safe and immunogenic, although annual vaccination would likely be required to maintain protective antibody levels.

T314

127197-127313

Epistemic_statement

denotes

Revaccination was immunogenic suggesting that annual vaccination may allow the maintenance of protective antibodies.

T315

129869-130078

Epistemic_statement

denotes

The overall tolerance profile was favorable, and an independent Experts Board recommended that clinical development should be continued, but with increased safety documentation in the phase III efficacy study.

T316

130699-130832

Epistemic_statement

denotes

In conclusion, these data indicate that BBG2Na + alum is immunogenic in the elderly and that a single dose regimen probably suffices.

T317

130833-130927

Epistemic_statement

denotes

However, safety monitoring would be an essential component for the phase III efficacy studies.

T318

132688-132814

Epistemic_statement

denotes

The young infants had minimal antibody responses, although there were detectable serum levels of IgG and IgA to the G protein.

T319

132926-133111

Epistemic_statement

denotes

A second dose of vaccine, the response to which can be used as a surrogate for reinfection, resulted in rare shedding of the virus and no evidence of enhanced RSV illness once infected.

T320

133112-133217

Epistemic_statement

denotes

These findings suggest that the vaccine may be protective without detectable increases in antibody level.

T321

133218-133479

Epistemic_statement

denotes

Finally, a NS-2 protein deleted 248/404 virus, a change that may make the virus more susceptible to interferon, has been found to have markedly reduced viral shedding, particularly in seronegative children, when compared to the other attenuated vaccine strains.

T322

133480-133672

Epistemic_statement

denotes

Although the study of these live-attenuated vaccines against RSV have given limited information about efficacy, they have given significant data to support continued develop of these vaccines.

T323

133752-134049

Epistemic_statement

denotes

One study found that 100% of children 0-12 years of age had experienced PIV3 infections and that ∼60% of children age 13-24 months and ∼35% of children age 25-36 months were later reinfected with the same strain, suggesting incomplete protection following primary infection (Glezen et al., 1984) .

T324

134050-134364

Epistemic_statement

denotes

Two different PIV3 vaccines are currently under development with the goal of preventing PIV-associated lower respiratory tract illness in those at risk: a live-attenuated bovine vaccine, which is being developed by MedImmune and NIH, and a cp45-based vaccine that is being developed cooperatively by Wyeth and NIH.

T325

134365-134585

Epistemic_statement

denotes

Although bovine PIV3 was well tolerated when used to vaccinate infants and children, only 70% of vaccinated children developed a four-fold rise in antibody titer, far less than would be seen with natural HPIV3 infection.

T326

135224-135527

Epistemic_statement

denotes

Additional potential uses of these recombinant PIV-3 viruses are as vectors to express PIV-1 and RSV F and G proteins, measles H protein, or surface glycoproteins of other respiratory viruses Durbin et al., 2000; Schmidt et al., 2000 Schmidt et al., , 2002 Skiadopoulos et al., 2001; Tao et al., 2000) .

T327

136141-136237

Epistemic_statement

denotes

This suggests that prior natural HPIV3 infection limits the infectiousness of the vaccine virus.

T328

136441-136662

Epistemic_statement

denotes

In these studies, the vaccine was well tolerated without significant adverse effects, although a small number of URIs and an increased number of otitis media episodes were observed in the phase I but not phase II studies.

T329

136663-136793

Epistemic_statement

denotes

Next, a two-dose study in 1-2-month-old infants was conducted, with the second dose being used as a surrogate challenge infection.

T330

137459-137729

Epistemic_statement

denotes

All five formed plaques at 39 • C, represented a small fraction (1%) of the total viral population, presented at the peak of viral shedding and were cleared at the same rate as fully temperature-sensitive viruses, and were not associated with changes in clinical status.

T331

137730-137884

Epistemic_statement

denotes

From these studies, it is clear that the cp45 HPIV3 vaccine is well-tolerated and immunogenic in infants and children but uncommonly may partially revert.

T332

137885-137990

Epistemic_statement

denotes

Multiple doses will be needed in infancy and the interval between doses should not be more than 2 months.

T333

139130-139260

Epistemic_statement

denotes

Further studies are planned to investigate the incidence of OM and the utility of two doses of both PIV3 and combination vaccines.

T334

139554-139671

Epistemic_statement

denotes

The intranasally administered vaccine has been shown previously to be safe and well tolerated in adults and children.

T335

140692-140811

Epistemic_statement

denotes

This LIV that is currently used in Russian appears to be safe, well tolerated, and effective in children 3-6 years old.

T336

141210-141370

Epistemic_statement

denotes

The H9N2 virus exhibits receptor-binding properties consistent with other human influenza viruses suggesting that this virus could potentially cause a pandemic.

T337

141431-141602

Epistemic_statement

denotes

Since whole virus vaccines may be more immunogenic in naïve patients, whole virion (WV) and subunit (SV) vaccines were prepared using influenza A/Hong Kong/0173/99 (H9N2).

T338

141978-142153

Epistemic_statement

denotes

Both vaccines were well tolerated, although the WV was associated with more frequent pain (42% versus 10%), nausea (15% versus 0%), and arthalgias (15% versus 3%) than the SV.

T339

142154-142327

Epistemic_statement

denotes

There were no differences in seroconversion between WV and SV at day 42, although seroconversion was more likely in patients who had received 30 g, particularly with the WV.

T340

142328-142439

Epistemic_statement

denotes

Patients younger than 32 years were less likely to convert after the first dose than following the second dose.

T341

142440-142536

Epistemic_statement

denotes

This suggests that a booster dose will be required for all naïve patients younger than 32 years.

T342

143508-143704

Epistemic_statement

denotes

Studies of these agents are difficult because it is unclear what are the optimal dose and formulation of Echinacea to use and what are the relative absorption and distribution of each preparation.

T343

144276-144472

Epistemic_statement

denotes

In summary, activities of Echinacea extracts are unclear, the products are not standardized, and the currently available studies provide limited data that can be generalized to different products.

T344

144473-144586

Epistemic_statement

denotes

Components of the pathogenesis of rhinoviral colds need to be considered as targets for therapeutic intervention.

T345

144847-144918

Epistemic_statement

denotes

Progression of the virus to the lower respiratory tract may also occur.

T346

144919-145002

Epistemic_statement

denotes

One step amenable to modification may be the oxidative stress induced by the virus.

T347

145420-145527

Epistemic_statement

denotes

NAC exposure was associated with significant decreases in NFB and IL-8 in a concentration-dependent manner.

T348

145699-145961

Epistemic_statement

denotes

Anti-ICAM exposure of cell culture was associated with a significant decrease in viral titer, but there was no difference in IL-8 production in wells exposed and unexposed to anti-ICAM, suggesting that elaboration of IL-8 is independent of viral binding to ICAM.

T349

147150-147310

Epistemic_statement

denotes

Future studies will be directed at specific inhibitors of NOX-4 to assess their ability to limit the viral titer and symptoms as the result of these infections.

T350

147651-147828

Epistemic_statement

denotes

Unfortunately, it had to be given in high doses six times a day to be effective, and has not been pursued for clinical development (Huguenel et al., 1997; Turner et al., 1999) .

T351

147829-148026

Epistemic_statement

denotes

A murine monoclonal antibody, termed RRMA, which blocked ICAM-1, was found to be safe in humans and partially effective in preventing experimental hRV infection in one trial (Hayden et al., 1988) .

T352

149157-149365

Epistemic_statement

denotes

The molecule is stable for over 3 months at 37 • C and for over a week in nasal mucus at 37 • C. As a result of these promising studies, the compound is being developed as an intranasal anti-rhinovirus agent.

T353

149654-149840

Epistemic_statement

denotes

CV-N is active in vitro against influenza but has little or no activity against adenovirus, parainfluenza virus, respiratory syncytial virus, enterovirus, rhinovirus, or coxsackie virus.

T354

150189-150340

Epistemic_statement

denotes

Europium-labeled CV-N bound to viral HA that contained high mannose residues, and exogenous oligomannose-8 could inhibit the binding of CV-N to the HA.

T355

151202-151541

Epistemic_statement

denotes

Ruprintrivir (AG7088) (Amy Patick, Pfizer Global Research and Development, La Jolla, CA) In the search for drugs active against picornaviruses, the 3C protease was identified as a important target because it lacks similarity to human proteases, is essential for replication, and has a highly conserved active site (Matthews et al., 1994) .

T356

154117-154239

Epistemic_statement

denotes

Pleconaril treatment was associated with a reduction in illness duration of 0.6 and 1.5 days in each study, respectively .

T357

154958-155139

Epistemic_statement

denotes

Three-and-a-half percent of women on oral contraceptives developed menstrual disorders after using pleconaril, although there was no increased incidence of pregnancy in these women.

T358

155761-155966

Epistemic_statement

denotes

The safety profile of pleconaril in this study was similar to the treatment study, although there was a two-to three-fold increased rate of menstrual disorders in pleconaril recipients compared to placebo.

T359

156193-156333

Epistemic_statement

denotes

This increased CYP3A activity was associated with a 35% decrease in the AUC of ethinyl estradiol and a 28% decrease in the AUC of midazolam.

T360

156435-156611

Epistemic_statement

denotes

It is interesting to note that there was no evidence that pleconaril had an impact on the cytochrome P450 system in preliminary studies in rat, dog, or human hepatocyte assays.

T361

156612-156934

Epistemic_statement

denotes

Although the FDA Advisory Panel that reviewed the application for pleconaril agreed that it was efficacious, there were concerns about drug interactions, development of antiviral resistance, its probable over-the-counter-like use if approved, and the generalizability of the available efficacy data to higher risk persons.

T362

156935-157021

Epistemic_statement

denotes

As a result of these concerns, the FDA deemed pleconaril not approvable in June, 2002.

T363

157518-157787

Epistemic_statement

denotes

Currently, pharmaceutical interest in compounds with activity against respiratory viruses is limited because of a focus on chronic disease, unattractive commercial opportunities, and the high standard required to obtain FDA approval for non-life-threatening conditions.

T364

157788-157959

Epistemic_statement

denotes

Despite these limitations, colds are the most common reason for seeing a physician and result in nearly 75% of patients taking over-the-counter medications or antibiotics.

T365

157960-158168

Epistemic_statement

denotes

Antiviral agents with activity against rhinoviruses are needed and may have additional benefits such as reducing the indiscriminant use of antibiotics with its resultant induction of antimicrobial resistance.

T366

158169-158391

Epistemic_statement

denotes

As has been described earlier, RSV is an important pathogen in infants, the elderly, and the immunocompromised and is responsible for over 100,000 excess hospitalizations and US$ 2 billion in direct medical costs annually.

T367

158392-158481

Epistemic_statement

denotes

Several compounds are under development that may be effective in treating RSV infections.

T368

158482-159018

Epistemic_statement

denotes

One such class of compounds inhibits RSV replication by affecting functions associated with the viral fusion (F) glycoprotein: Janssen's R170591, a topically applied compound with a reported EC 50 against RSV of <1 nM, is in preclinical study; Bristol-Myers Squibb's BMS-433771, an orally bioavailable compound with a reported EC 50 against RSV of 10 nM, is in preclinical study; and ViroPharma's VP14637, a compound delivered by small particle aerosol (SPA) inhalation with an EC 50 against RSV of <1 nM, is completing phase 1 studies.

T369

159091-159238

Epistemic_statement

denotes

In vitro time of drug addition studies suggest that the drug has to be present early after infection to affect a single round of virus replication.

T370

160044-160179

Epistemic_statement

denotes

A phase 1 study has recently been completed, although data analysis is ongoing, and other studies are in the planning stages currently.

T371

160180-160481

Epistemic_statement

denotes

(Mikhail Matrosovich, Philipps University, Marburg, Germany) Influenza virus can develop resistance to neuraminidase inhibitors via changes in the neuraminidase (NA), which results in decreased drug binding, or in the hemagglutinin (HA), which results in lowered HA affinity for its cellular receptor.

T372

160482-160595

Epistemic_statement

denotes

To detect both types of resistance, and perhaps novel ones, a virus inhibition assay in cell culture is required.

T373

160596-160925

Epistemic_statement

denotes

Unfortunately, current cell culture assays are not predictive of influenza virus sensitivity to neuraminidase inhibitors (NAI) in enzyme inhibition assays or in vivo (McKimm-Breschkin, 2000; Tisdale, 2000) NAI sensitive strains may appear to be resistant, while NAI resistant mutants may show susceptibility with current methods.

T374

160926-161057

Epistemic_statement

denotes

One reason for this limitation is that laboratory cell lines do not model influenza virus receptors in the human airway epithelium.

T375

161784-161940

Epistemic_statement

denotes

Preliminary studies demonstrated that the transfection was stable and resulted in substantially increased two to six linked sialic acid on the cell surface.

T376

162615-162715

Epistemic_statement

denotes

The drug susceptibility patterns correlated with the affinity for 6-linked receptors of the viruses.

T377

162716-162914

Epistemic_statement

denotes

In summary, the SIAT-transfected MDCK cells have acquired genes that are stably expressed and result in increased expression of 6-linked sialic acids and reduced expression of 3-linked sialic acids.

T378

163231-163344

Epistemic_statement

denotes

The SIAT1 transfected MDCK cells appear to be a promising system for testing influenza virus sensitivity to NAIs.

T379

164042-164284

Epistemic_statement

denotes

The Neuraminidase Inhibitor Susceptibility Network (NISN) was established to monitor the potential development of resistance in clinical isolates with the widespread introduction of NA inhibitors into clinical practice (Zambon et al., 2001) .

T380

164573-164802

Epistemic_statement

denotes

Preliminary testing showed that the MUNANA fluorescent assay (Potier et al., 1979) and NA-STAR chemiluminescent assay (Buxton et al., 2000) gave similar results, although the NA-STAR method was preferred when NA activity was low.

T381

165454-165641

Epistemic_statement

denotes

One of 10 N1, 7 of 38 N2, and 1 of 42 influenza B isolates had D151 to N, G, E, or V. Originally the D151 was thought to be the proton donor for the catalytic reaction mediated by the NA.

T382

165642-165748

Epistemic_statement

denotes

Since none of these isolates showed decreased enzyme activity, the D151 likely does not provide this role.

T383

165749-165961

Epistemic_statement

denotes

In addition to changes in non-conserved residues associated with natural antigen drift, there was also a change in the conserved residue T225I in 1 B virus, and co-evolution of I203L and E375G in 5/42 B isolates.

T384

165962-166124

Epistemic_statement

denotes

Molecular modeling shows these latter two residues lie on opposite sides of the NA head and hence are more likely to be random rather than compensatory mutations.

T385

166125-166246

Epistemic_statement

denotes

Importantly, despite sequence variations, there was no naturally occurring resistance to either zanamivir or oseltamivir.

T386

166252-166618

Epistemic_statement

denotes

Effect of mutations in the hemagglutinin gene of influenza A viruses on the resistance phenotype of neuraminidase inhibitors (Guy Boivin, Laval University, Québec, Canada) Previous studies have shown that resistance to neuraminidase inhibitors (NAI) generated after in vitro passages may result in mutations in the neuraminidase (NA) and/or hemagglutinin (HA) genes.

T387

166619-166734

Epistemic_statement

denotes

However, the effect of HA mutations alone on the resistance phenotype remains to be confirmed in clinical isolates.

T388

167501-167633

Epistemic_statement

denotes

This data suggests that in vitro generated resistance to NAIs may not be solely attributable to HA mutations as previously reported.

T389

167634-167786

Epistemic_statement

denotes

In addition, the combined effects of HA and NA mutations needs to be investigated as potential mechanisms for NAI resistance (Nedyalkova et al., 2002) .

T390

168116-168304

Epistemic_statement

denotes

Two additional orally active neuraminidase inhibitors (NAI), peramivir and A-315675, are investigational, although there are no current plans to move these agents forward for clinical use.

T391

168305-168515

Epistemic_statement

denotes

In vitro resistance can be mediated by changes in the hemagglutinin (HA), which is strain-specific, change in neuraminidase (NA), which is both subtype-and drug-specific, both, or by creation of a defective NA.

T392

168718-168888

Epistemic_statement

denotes

These results of these assays are affected if the reaction conditions are varied, even slightly, if there are mixtures of variants present, or if the NA has low activity.

T393

168889-169025

Epistemic_statement

denotes

Resistance may be defined as a 5-10-fold or greater increase in the IC 50 values compared to the virus recovered prior to drug exposure.

T394

169026-169153

Epistemic_statement

denotes

Sequencing of the NA or HA genes can be done to document genetic changes that may be associated with the phenotypic resistance.

T395

169442-169589

Epistemic_statement

denotes

However, several oseltamivir-selected changes in the NA of influenza A viruses have been detected: N1 H274T and N2 G119V and R292K have been found.

T396

172042-172260

Epistemic_statement

denotes

Over time, a G119V NA mutation occurred which conferred resistance to oseltamivir only and an S31N M2 mutation conferred M2 inhibitor resistance, so that a virus resistant to both M2 inhibitors and oseltamivir emerged.

T397

172261-172403

Epistemic_statement

denotes

From these patients, it is clear that antiviral therapy failed to control the influenza infection and that novel NA mutations were recognized.

T398

172646-172729

Epistemic_statement

denotes

The mechanisms of resistance to NAIs are complex and require further investigation.

T399

172730-172873

Epistemic_statement

denotes

Future studies should assess the impact of HA mutations and sialyation of HA on the virus dependence on the NA activity and NAI susceptibility.

T400

173274-173470

Epistemic_statement

denotes

The recent events associated with the SARS epidemic and outbreak of influenza A/H7N7 in Europe further emphasize the importance of planning ahead for pandemics and potential biologic catastrophes.

T401

173635-173771

Epistemic_statement

denotes

The development of live-attenuated and recombinant vaccines holds great promise for preventing viral respiratory diseases in the future.

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