Data approvals were obtained from the National Research Ethics Service Committee, Southeast Scotland 02 (12/SS/0201), and the Public Benefit and Privacy Panel for Health and Social Care (HSC-PBPP; 0920-0279). The data are stored in the Public Health Scotland Trusted Research Environment. To access these individual-level, confidential health-care data, researchers should apply to the HSC-PBPP (https://www.informationgovernance.scot.nhs.uk/pbpphsc/). AS has served on COVID-19 advisory groups for the UK and Scottish Governments and for AstraZeneca, all of which have been unremunerated. AS holds a research grant on the effectiveness and safety of monoclonal antibodies from GSK. This Correspondence was supported by the Medical Research Council (UKRIMC_PC19075) and the National Institute for Health and Care Research (NIHR135575). We thank Lynn Laidlaw and Kamil Sterniczuk for their contributions to the development of this Correspondence. For the purpose of open access, the authors have applied a CC-BY public copyright licence to any Author Accepted Manuscript version arising from this Correspondence.