Id |
Subject |
Object |
Predicate |
Lexical cue |
T187 |
0-249 |
Sentence |
denotes |
The kinetics of SARS-CoV-2 IgG was studied up to 165 days after positive SARS-CoV-2 PCR results by the analysis of consecutive samples from 11 patients and samples from five routine patients; four are family members of a SARS-CoV-2-infected patient. |
T188 |
250-377 |
Sentence |
denotes |
The results were obtained with two IgG assays based on the N (Abbott) or the entire S (Virion-Serion) antigens as the epitopes. |
T189 |
378-502 |
Sentence |
denotes |
Both tests turned out to be the most sensitive and specific assays in the validation part of our study (compare in Table 1). |
T190 |
503-578 |
Sentence |
denotes |
Thereby, SARS-CoV-2-specific antibodies were detectable in all individuals. |
T191 |
579-823 |
Sentence |
denotes |
While the N-based IgG assay revealed the existence of two groups of individuals, and one of them showed a rapid decrease of IgG indices within a few months, the IgG reactivity in the S protein-based assay was found to be more stable (Figure 4). |
T192 |
824-1007 |
Sentence |
denotes |
This is in-line with a previous preprint [16] and could suggest that the latter test is better suited for epidemiological studies, especially when it comes to questions of prevalence. |
T193 |
1008-1113 |
Sentence |
denotes |
Accordingly, the majority of SARS-CoV-2-infected patients in our study developed neutralizing antibodies. |
T194 |
1114-1236 |
Sentence |
denotes |
The titers were stable during the observation period but were in a relatively low range between >1:10 and 1:80 (Figure 5). |
T195 |
1237-1327 |
Sentence |
denotes |
Only three patients showed conversion from low to high SARS-CoV-2 IgG avidity (Figure S3). |
T196 |
1328-1439 |
Sentence |
denotes |
The limited number of included SARS-CoV-2 patients, however, limits the informative value of the present study. |
T197 |
1440-1686 |
Sentence |
denotes |
The evaluability of the simple and reproducible PRNT technique applied here may be improved by overlaying the cells with cellulose or by using specific antibodies to detect the remaining viral antigens in the cells, as reported previously [7,20]. |
T198 |
1687-1870 |
Sentence |
denotes |
Furthermore, the application of a modified cytopathic effect inhibition assay [30] may be useful to facilitate standardization and quantification and will be valued in future studies. |
T199 |
1871-2025 |
Sentence |
denotes |
Several SARS-CoV-2-infected patients and routine patients in our study lost their SARS-CoV-2 (N)-specific IgG within a few months or could lose them soon. |
T200 |
2026-2205 |
Sentence |
denotes |
These individuals can theoretically be prone to reinfection, especially since the S-specific IgG and the neutralizing antibodies are stable but only present in low indices/titers. |
T201 |
2206-2248 |
Sentence |
denotes |
In a few patients, both were undetectable. |
T202 |
2249-2373 |
Sentence |
denotes |
However, this view does not take into account the booster effect that can be expected in the event of renewed virus contact. |
T203 |
2374-2441 |
Sentence |
denotes |
This would most likely lead to a rapid increase in antibody titers. |
T204 |
2442-2584 |
Sentence |
denotes |
Accordingly, vaccine strategies against SARS-CoV-2 may need boosting to maintain sufficient neutralizing antibody titers over a long time [5]. |
T205 |
2585-2700 |
Sentence |
denotes |
Waning antibody titers and reinfections are known from various HCoVs mainly responsible for common colds [5,12,31]. |
T206 |
2701-2793 |
Sentence |
denotes |
Recently a well-documented case of an asymptomatic SARS-CoV-2 reinfection was reported [32]. |
T207 |
2794-2911 |
Sentence |
denotes |
In our opinion, the importance of such rare events for the progression of the temporary pandemic appears to be minor. |
T208 |
2912-3017 |
Sentence |
denotes |
Nevertheless, a permanent presence of measurable SARS-CoV-2 IgG in the serum of all patients is unlikely. |
T209 |
3018-3174 |
Sentence |
denotes |
This is not surprising and has also been observed in patients after infections with SARS-CoV (2002/2003) or Middle East respiratory syndrome (MERS)-CoV [5]. |
T210 |
3175-3269 |
Sentence |
denotes |
It does not necessarily mean that these individuals will be susceptible to severe reinfection. |