ALG reports grants from Novavax to run vaccine trials and non-commercial funding from the INSIGHT network (NIH-TICO trial) to her institution outside of the submitted work; ALG is also named as an inventor on a patent issued to the University of Oxford covering use of a promotor construct incorporated in the ChAdOx1 nCoV-19 vaccine developed by AstraZeneca and the University of Oxford. RKG reports personal fees from GlaxoSmithKline, Johnson & Johnson, and UMOVIS Lab, and a research grant from Invisi Smart Technologies, outside of the submitted work. SJ reports grants from CSL Behring and Takeda and personal fees from CSL Behring, Octapharma, Pharming, Takeda, LFB, Grifols, Biotest, and UCB pharma, outside of the submitted work; SJ also served on advisory boards for CSL Behring, Octapharma, Pharming, LFB, Grifols, and Biotest, and on data and safety monitoring boards for Biotest and UCB Pharma, outside of the submitted work. DKM served as one of the principal investigators for the UK Convalescent Plasma Trial in critically ill patients with COVID-19, conducted as part of the REMAP-CAP Trial. MS-H reports a grant from the National Institute for Health Research (NIHR Clinician Scientist Fellowship; NIHR-CS–2016-16-011), during the conduct of the study, and served as Clinical Lead for the UK Convalescent Plasma Trial in critically ill patients with COVID-19, conducted as part of the REMAP-CAP Trial. DML reports non-financial support (travel and subsistence costs) from CSL Behring, personal fees from Merck, and grants from LifeArc, the British Society for Antimicrobial Chemotherapy, Blood Cancer UK, Bristol Myers Squibb, and the UK Medical Research Council, outside of the submitted work. All other authors declare no competing interests.