Abstract
In addition to serum immunoglobulins, memory B cell (MBC) generation against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is another layer of immune protection, but the quality of MBC responses in naive and coronavirus disease 2019 (COVID-19)-recovered individuals after vaccination remains ill defined. We studied longitudinal cohorts of naive and disease-recovered individuals for up to 2 months after SARS-CoV-2 mRNA vaccination. We assessed the quality of the memory response by analysis of antibody repertoires, affinity, and neutralization against variants of concern (VOCs) using unbiased cultures of 2,452 MBCs. Upon boosting, the MBC pool of recovered individuals expanded selectively, matured further, and harbored potent neutralizers against VOCs. Although naive individuals had weaker neutralizing serum responses, half of their RBD-specific MBCs displayed high affinity toward multiple VOCs, including delta (B.1.617.2), and one-third retained neutralizing potency against beta (B.1.351). Our data suggest that an additional challenge in naive vaccinees could recall such affinity-matured MBCs and allow them to respond efficiently to VOCs.
Keywords: B-cell memory; BNT162b2 vaccine; COVID-19; RBD; affinity maturation; germinal center; neutralizing antibody; plasma cells; somatic hypermutation.
【저자키워드】 COVID-19, neutralizing antibody, BNT162b2 vaccine, RBD, Germinal center, Somatic hypermutation, Affinity maturation, Plasma cells, B-cell memory, 【초록키워드】 coronavirus disease, neutralizing antibody, SARS-CoV-2, mRNA vaccination, Coronavirus disease 2019, BNT162b2 vaccine, coronavirus, vaccination, antibody, B.1.351, neutralization, immunoglobulins, variants of concern, B.1.617.2, severe acute respiratory syndrome Coronavirus, variants, memory, BNT162b2, serum, Cohort, Culture, response, VOCs, plasma, Germinal center, Beta, Neutralizing, recall, respiratory, memory B cell, Affinity maturation, MBC, affinity, immune protection, B-cell, Plasma cells, memory response, Analysis, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, naïve individuals, individual, high affinity, serum immunoglobulins, MBCs, naïve vaccinees, responses, Cell, memory B, vaccinee, defined, addition, retained, respond, 【제목키워드】 mRNA vaccination, SARS-CoV-2 variant, individual, recognize, elicit,