Anti-spike antibody response to natural SARS-CoV-2 infection in the general population
Wei J., Matthews P., Stoesser N., Maddox T., Lorenzi L., Studley R., Bell J., Newton J., Farrar J., Diamond I., Rourke E., Howarth A., Marsden B., Hoosdally S., Jones Y., Stuart D., Crook D., Peto T., Pouwels K., Walker S., Eyre D., the COVID-19 Infection Survey team None.
We estimated the duration and determinants of antibody response after SARS-CoV-2 infection in the general population using representative data from 7,256 United Kingdom COVID-19 infection survey participants who had positive swab SARS-CoV-2 PCR tests from 26-April-2020 to 14-June-2021. A latent class model classified 24% of participants as ‘non-responders’ not developing anti-spike antibodies. These seronegative non-responders were older, had higher SARS-CoV-2 cycle threshold values during infection (i.e. lower viral burden), and less frequently reported any symptoms. Among those who seroconverted, using Bayesian linear mixed models, the estimated anti-spike IgG peak level was 7.3-fold higher than the level previously associated with 50% protection against reinfection, with higher peak levels in older participants and those of non-white ethnicity. The estimated anti-spike IgG half-life was 184 days, being longer in females and those of white ethnicity. We estimated antibody levels associated with protection against reinfection likely last 1.5-2 years on average, with levels associated with protection from severe infection present for several years. These estimates could inform planning for vaccination booster strategies.