Characterizing the kinetics of the antibody response to SARS‐CoV‐2 is of critical importance to developing strategies that may mitigate the public health burden of COVID-19. In this study the authors conducted a prospective, longitudinal analysis of COVID-19 convalescent plasma (CCP) donors at multiple time points over an 11-month period in order to determine how circulating antibody levels change over time following natural infection. From April 2020 to February 2021, they enrolled 228 donors. At each study visit, subjects either donated plasma or had study samples drawn only. Anti-SARS-CoV-2 donor testing was performed using the VITROS® Anti-SARS-CoV-2 Total and IgG assays, and an in-house fluorescence reduction neutralization assay (FRNA). Anti-SARS-CoV-2 antibodies were identified in 97% of COVID-19 convalescent donors at initial presentation. In follow up analyses, of the 116 donors presenting for repeat timepoints, 91.4% of donors had detectable IgG levels up to 11 months post-symptom recovery, while 63% had detectable neutralizing titers, however, we observed that 25% of donors had neutralizing levels that dropped to an undetectable titer over time.
The authors concluded that their data suggest that immunological memory is acquired in most individuals infected with SARS-CoV-2 and is sustained in a majority of patients for up to 11 months after recovery.
Valeria De Giorgi, Kamille A West, Amanda N Henning, Leonard N Chen, Michael R Holbrook, Robin Gross, Janie Liang, Elena Postnikova, Joni Trenbeath, Sarah Pogue, Tania Scinto, Harvey J Alter, Cathy Conry Cantilena, Naturally acquired SARS-CoV-2 immunity persists for up to 11 months following infection, The Journal of Infectious Diseases, 2021;, jiab295, https://doi.org/10.1093/infdis/jiab295