Severe acute respiratory syndrome coronavirus-2 vaccine-induced B cells aspire to long-lived connections: Tracking B-cell memory over time

Abstract

It is vitally important that we understand whether mRNA vaccines are capable of generating high-affinity, longlived immune memory cells to SARS-CoV-2. To this end, a recent study by Ellebedy, Kim and colleagues provide much-needed insight into the production and quality of humoral immune cells generated by the BNT162b2 vaccine.

Figure 1

Schematic representation of the B‐cell response to BNT162b2 vaccine. (a) During an initial T‐dependent humoral immune response to immunization or infection, the germinal center (GC) is critical for production of affinity‐matured memory B cells and plasma cell (PC) populations. (b) Schematic representation of the B‐cell response to BNT162b2. The B‐cell response to BNT162b2 can result in GCs that persist within the LNs for at least 6 months after vaccination. S‐specific GC B cells and lymph node PCs (LNPCs) cumulatively gain IGHV mutations over time. Circulating plasmablasts, conversely, do not gain mutations at the same rate. Bone marrow‐resident PCs (BMPCs) were detected more than 6 months after vaccination and were phylogenetically linked to the GC‐derived LNPCs via B‐cell receptor (BCR) mutation analysis. Serum anti‐S immunoglobulin G (IgG)‐binding avidity increased in uninfected vaccinated individuals, reflecting observed increases in IGHV mutation frequency; however, individuals with a prior history of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection did not experience a change in their antibody avidity between 5 and 29 weeks.