Humoral Response Dynamics Following Infection with SARS-CoV-2

Grandjean, L.; Saso, A.; Ortiz, A.; Lam, T.; Hatcher, J.; Thistlethwaite, R.; Harris, M.; Best, T.; Johnson, M.; Wagstaffe, H.; Ralph, E.; Mai, A.; Colijn, C.; Breuer, J.; Buckland, M.; Gilmour, K.; Goldblatt, D.; Team, The Co-Stars Study

Objectives To understand humoral dynamics following SARS-CoV-2 infection Design Prospective Cohort Study Setting Great Ormond Street Hospital (Central London Paediatric Hospital) Participants 67 healthcare workers aged >18 years who provided monthly serial serological samples from 29th April 2020 until 30th June 2020. Main outcome measures The change in monthly serial antibody titers to SARS-CoV-2 nucleoprotein (N), spike protein and the receptor binding domain of the spike protein. Results The mean estimated half-life of the nucleoprotein antibody was 52 days (95% CI 42-65). The spike and RBD antibody had significantly longer mean half-lives of 81 days (95% CI 61-111) and 83 days (95% CI 55-137) respectively. An ACE-2 receptor competition assay demonstrated significant correlation between the spike and RBD antibody titers and ACE2 receptor blocking in-vitro. The time to a negative nucleoprotein antibody test for 50% of the seropositive population was predicted to be 195 days (95% CI 163-236). Conclusions After SARS-CoV-2 infection, the predicted half-life of nucleoprotein antibody was 52 days with 50% of seropositives becoming seronegative to this antibody at 195 days. Widely used serological tests including the Public Health England endorsed assay that depend on the nucleoprotein antibody will therefore underestimate the true prevalence of infection within a year following the majority of infections.