The study protocol is available at https://isaric4c.net/protocols; study registry https://www.isrctn.com/ISRCTN66726260. This work uses data provided by patients and collected by the NHS as part of their care and support #DataSavesLives. We are grateful to the 2648 frontline NHS clinical and research staff and volunteer medical students who collected the data in challenging circumstances; and the generosity of the participants and their families for their individual contributions in these difficult times. We also acknowledge the support of Jeremy J Farrar, Nahoko Shindo, Devika Dixit, Nipunie Rajapakse, Lyndsey Castle, Martha Buckley, Debbie Malden, Katherine Newell, Kwame O’Neill, Emmanuelle Denis, Claire Petersen, Scott Mullaney, Sue MacFarlane, Nicole Maziere, Julien Martinez, Oslem Dincarslan, and Annette Lake.

Funding
This work is supported by grants from: the National Institute for Health Research (NIHR; award CO-CIN-01), the Medical Research Council (MRC; grant MC_PC_19059), and by the NIHR Health Protection Research Unit (HPRU) in Emerging and Zoonotic Infections at University of Liverpool in partnership with Public Health England (PHE), in collaboration with Liverpool School of Tropical Medicine and the University of Oxford (award 200907), NIHR HPRU in Respiratory Infections at Imperial College London with PHE (award 200927), Wellcome Trust and Department for International Development (DID; 215091/Z/18/Z), the Bill and Melinda Gates Foundation (OPP1209135), Liverpool Experimental Cancer Medicine Centre (grant reference C18616/A25153), NIHR Biomedical Research Centre at Imperial College London (IS-BRC-1215-20013), EU Platform for European Preparedness Against (Re-)emerging Epidemics (PREPARE; FP7 project 602525), and NIHR Clinical Research Network for providing infrastructure support for this research. PJMO is supported by a NIHR senior investigator award (201385). LT is supported by the Wellcome Trust (award 205228/Z/16/Z). MN is funded by a WT investigator award (207511/Z/17/Z) and the NIHR University College London Hospitals Biomedical Research Centre. The views expressed are those of the authors and not necessarily those of the Department of Health and Social Care, DID, NIHR, MRC, Wellcome Trust, or PHE. Contributors
Conceptualisation: SRK, AH, RP, GC, JD, PWH, LM, JSN-V-T, CS, PJMO, JKB, MGS, ABD, EMH; data curation: RP, SH, KAH, CJ, CAG, KAM, LM, LN, CDR, CAS, MGS, ABD, EMH; formal analysis: SRK, AH, RP, TMD, CJF, KAM, MGP, LCWT, EMH. Funding acquisition: PWH, JSN-V-T, TS, PJMO, JKB, MGS, ABD. Investigation: SRK, AH, CDR, OVS, LCWT, PJMO, JKB, MGS, ABD, EMH; methodology: SRK, AH, RP, IB, KAM, CAS, AS, CS, ABD, EMH; project administration: SH, HEH, CJ, LM, LN, CDR, CAS, MGS; resources: CG, PWH, LM, TS, MGS, EMH; software: SRK, RP, KAM, OVS; supervision: SRK, RP, CG, HEH, PWH, PLO, PJMO, JKB, MGS, EMH; visualisation: SRK, RP, MGP, EMH; writing-original draft: SRK, EMH; writing-review and editing: SRK, RG, AH, RP, IB, GC, TMD, CAG, JD, CJF, LM, MN, JSN-V-T, PLO, MGP, CDR, AS, CS, OVS, LCWT, PJMO, JKB, MGS, ABD, EMH. SRK and AH are joint first authors. MGS, ABD, and EMH are joint senior authors. MGS is guarantor and corresponding author for this work, and attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.
Competing interests
All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: support from the National Institute for Health Research (NIHR), the Medical Research Council (MRC), the NIHR Health Protection Research Unit (HPRU) in Emerging and Zoonotic Infections at University of Liverpool, Public Health England (PHE), Liverpool School of Tropical Medicine, University of Oxford, NIHR HPRU in Respiratory Infections at Imperial College London, Wellcome Trust, Department for International Development, the Bill and Melinda Gates Foundation, Liverpool Experimental Cancer Medicine Centre, NIHR Biomedical Research Centre at Imperial College London, EU Platform for European Preparedness Against (Re-)emerging Epidemics (PREPARE), and NIHR Clinical Research Network for the submitted work; ABD reports grants from Department of Health and Social Care (DHSC), during the conduct of the study, grants from Wellcome Trust, outside the submitted work; CAG reports grants from DHSC National Institute of Health Research (NIHR) UK, during the conduct of the study; PWH reports grants from Wellcome Trust, Department for International Development, Bill and Melinda Gates Foundation, NIHR, during the conduct of the study; JSN-V-T reports grants from DHSC, England, during the conduct of the study, and is seconded to DHSC, England; MN is supported by a Wellcome Trust investigator award and the NIHR University College London Hospitals Biomedical Research Centre (BRC); PJMO reports personal fees from consultancies and from European Respiratory Society, grants from MRC, MRC Global Challenge Research Fund, EU, NIHR BRC, MRC/GSK, Wellcome Trust, NIHR (Health Protection Research Unit (HPRU) in Respiratory Infection), and is NIHR senior investigator outside the submitted work; his role as President of the British Society for Immunology was unpaid but travel and accommodation at some meetings was provided by the Society; JKB reports grants from MRC UK; MGS reports grants from DHSC NIHR UK, grants from MRC UK, grants from HPRU in Emerging and Zoonotic Infections, University of Liverpool, during the conduct of the study, other from Integrum Scientific LLC, Greensboro, NC, USA, outside the submitted work; LCWT reports grants from HPRU in Emerging and Zoonotic Infections, University of Liverpool, during the conduct of the study, and grants from Wellcome Trust outside the submitted work; EMH, HEH, JD, RG, RP, LN, KAH, GC, LM, SH, CJ, and CG, all declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; and no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval
Ethical approval was given by the South Central-Oxford C Research Ethics Committee in England (reference 13/ SC/0149), and by the Scotland A Research Ethics Committee (reference 20/SS/0028). The study was registered at https://www.isrctn.com/ISRCTN66726260.
Data sharing
We welcome applications for data and material access via our Independent Data and Material Access Committee (https://isaric4c.net).
The lead author (the manuscript’s guarantor) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.
Dissemination to participants and related patient and public communities
ISARIC-4C has a public facing website isaric4c.net and twitter account (@CCPUKstudy). We are engaging with print and internet press, television, radio, news, and documentary programme makers. We will explore distribution of findings with The Asthma UK and British Lung Foundation Partnership and take advice from NIHR Involve and GenerationR Alliance Young People’s Advisory Groups.
Provenance and peer review statement
Not commissioned; externally peer reviewed.