The Effect of Waning on Antibody Levels and Memory B Cell Recall following SARS-CoV-2 Infection or Vaccination

• Published in: Vaccines (Basel) Vol. 10; no. 5; p. 696
• Main Authors: Forgacs, David, Silva-Moraes, Vanessa, Sautto, Giuseppe A, Hanley, Hannah B, Gattiker, Jasper L, Jefferson, Alexandria M, Kolhe, Ravindra, Ross, Ted M
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 29.04.2022; MDPI
• Subjects: Antibodies; antibody decay; Antigens; Cell differentiation; Coronaviruses; COVID-19; COVID-19 vaccines; Disease transmission; Immunological memory; infection; Infections; Lymphocytes B; Memory cells; mRNA; Pandemics; Peripheral blood mononuclear cells; Proteins; Recall; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Vaccination; Vaccines; waning; United States > US; COVID-19; antibody decay; SARS-CoV-2; infection; waning; antibody secreting cells; memory B cell recall; pre-immunity; vaccination
• ISSN: 2076-393X; 2076-393X
• DOI: 10.3390/vaccines10050696

In order to longitudinally track SARS-CoV-2 antibody levels after vaccination or infection, we assessed anti-RBD antibody levels in over 1000 people and found no significant decrease in antibody levels during the first 14 months after infection in unvaccinated participants, however, a significant waning of antibody levels was observed following vaccination. Participants who were pre-immune to SARS-CoV-2 prior to vaccination seroconverted to higher antibody levels, which were maintained at higher levels than in previously infected, unvaccinated participants. Older participants exhibited lower level of antibodies after vaccination, but a higher level after infection than younger people. The rate of antibody waning was not affected by pre-immunity or age. Participants who received a third dose of an mRNA vaccine not only increased their antibody levels ~14-fold, but also had ~3 times more antibodies compared to when they received their primary vaccine series. PBMC-derived memory B cells from 13 participants who lost all circulating antibodies were differentiated into antibody secreting cells (ASCs). There was a significant recall of memory B cell ASCs in the absence of serum antibodies in 5-8 of the 10 vaccinated participants, but not in any of the 3 infected participants, suggesting a strong connection between antibody levels and the effectiveness of memory B cell recall.