Persistent Maintenance of Atypical Memory B Cells Following SARS-CoV-2 Infection and Vaccination Recall Response

Abstract

Robust population-wide immunity will help to curb the SARS-CoV-2 pandemics. To maintain the immunity at protective levels, the quality and persistence of the immune response elicited by infection or vaccination have to be determined. We analyzed the dynamics of B cell response during 12 months following SARS-CoV-2 infection on an individual level. In contrast to antibodies, memory B cells specific for the spike (S) protein persisted at high levels throughout the period. These cells efficiently secreted neutralizing antibodies and correlated with IFNγ-secreting CD4+ T cells. Interestingly, the atypical CD27-CD21+ memory B cell phenotype was associated with high B cell receptor avidity and the production of neutralizing antibodies. Vaccination of previously infected individuals triggered a recall response enhancing neutralizing antibody and memory B cell levels. Collectively, our findings provide a detailed insight into the longevity of SARS-CoV-2-infection-induced B cell immunity and highlight the importance of vaccination among previously infected.

Funding Information: The government of North Rhine-Westphalia (Germany) supported the study finically (I B 3-2634).

Conflict of Interests: The authors declare no competing interests.

Ethical Approval: All participants provided written informed consent approved by the Ethics Committee of the Medical Faculty of the University of Bonn (ethics approval numbers 085/20 and 372/20).

Keywords: SARS-CoV-2, immunity, COVID-19, memory B cells, spike, CD4+ T cell, antibody, neutralization, recovered, vaccination, longevity, longitudinal, kinetics