Presence of SARS-CoV-2 antibodies following COVID-19 diagnosis: a longitudinal study of patients at a major urgent care provider in New York

Abstract

The duration of antibody persistence following natural infection is unclear. We examined routine SARS-CoV-2 diagnostic and serological testing data on 6522 persons diagnosed between March 2020 and March 2021 who had at least 1 antibody test ≥30 days after diagnosis at CityMD, an urgent care provider. Using survival analysis, we estimated the median duration of detectable anti-SARS-CoV-2 antibodies and hazard of seroreversion by demographic and clinical characteristics. We found that over 90% (95% CI: 91.8%, 94.8%) of the study population had detectable levels of antibodies at 180 days post diagnosis and that SARS-CoV-2 antibodies persisted at a detectable level for a median duration of 342 days following infection (95% CI: 328, 361). Additionally, there were differences in antibody persistence by age, with older patients less likely to serorevert compared to younger patients. These findings suggest that protection from natural infection may wane with time and differ by demographic factors.

Keywords: COVID-19; SARS-CoV-2; antibody; persistence; survival analysis.

Fig. 1

Patient selection into study sample to measure SARS-COV2 antibody persistence, March 1, 2020 to February 15, 2021.

Fig. 2

Survival curve and 95% confidence intervals for SARS-CoV-2 anti-nucleocapsid antibody persistence. Kaplan Meier method used for survival probability. Dashed line indicates median duration of antibody persistence.