Functional heterogeneity in the memory B-cell response

Most vaccines induce robust antibody and memory B-cell (MBC) responses that are capable of mediating protective immunity. However, antibody titers wane following vaccination necessitating the administration of booster vaccines to maintain a protective antibody titer. MBCs are stably maintained following vaccination and can rapidly give rise to antibody -secreting cells or undergo further affinity maturation upon antigen re-encounter. Repeated antigen encounter results in the development of MBCs that encode antibodies capable of mediating broadly protective immunity against viruses such as SARS-CoV-2 and influenza. Here, we summarize emerging evidence that MBCs are a heterogeneous population composed of transcriptionally and phenotypically distinct subsets that have discrete roles in mediating protective immunity upon antigen re-encounter and examine the implications of these findings for the development of vaccines capable of eliciting broadly protective immunity.

Automated summary

Vaccines can generate antibody and memory B-cell responses for protective immunity. However, antibody levels decrease over time, leading to the need for booster vaccines. Memory B-cells can persist after vaccination and quickly produce antibody-secreting cells or undergo maturation upon antigen re-encounter. Repeated antigen exposure results in memory B-cells encoding antibodies capable of broadly protective immunity against viruses like SARS-CoV-2 and influenza. In this review, we highlight emerging evidence showing the heterogeneity of memory B-cells and their distinct roles in mediating protective immunity upon antigen re-encounter, and discuss the implications for developing vaccines that elicit broadly protective immunity.