We report dynamics of seroconversion to SARS-CoV-2 infections detected by IgG ELISA in 177 individuals diagnosed by RT-PCR. Longitudinal analysis identifies 2-8.5% of individuals who do not seroconvert even weeks after infection. They are younger than seroconverters who have increased co-morbidity and higher inflammatory markers such as C-Reactive Protein. Higher antibody responses are associated with non-white ethnicity. Antibody responses do not decline during follow up almost to 2 months. Serological assays increase understanding of disease severity. Their application in regular surveillance will clarify the duration and protective nature of humoral responses to SARS-CoV-2.
Competing Interest Statement
SK is a member of the Scientific Advisory Committee for the Foundation for Innovative New Diagnostics (FIND) a not-for-profit organisation that produces global guidance on affordable diagnostics. The views expressed here are personal opinions and do not represent the recommendations of FIND.
This study was supported by a DFID/Wellcome Trust Epidemic Preparedness coronavirus grant (220764/Z/20/Z) to JRAF, SK, HMS, ERA, LEC. HMS is supported by the Wellcome Trust Institutional Strategic Support Fund (204809/Z/16/Z) awarded to St Georges University of London.
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Institutional Review Board ethical approval (DARTS study – IRAS project ID: 282104; REC reference: 20/SC/0171).
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