Figure 3.

Distribution of hCoV spike-specific, SARS-CoV-2 spike-specific, and SARS-CoV-2 spike/RBD-specific cells within individual MBC clusters.

For illustrative purposes, the dataset featured in [69] was assessed for the number of hCoV spike-specific, SARS-CoV-2 spike-specific, and SARS-CoV-2 spike/RBD-specific cells identified within individual MBC-identified clusters (4,6,7,8) at the 4.5-month convalescent timepoint. Presented are the absolute number of indicated antigen-specific cells detected, per indicated cluster. This represents a preliminary analysis that requires further experimental substantiation; however, these data suggest that MBC responses to different pathogens, or of different maturation levels (i.e., with different durations postexposure) may exhibit different subset distributions within the broader MBC compartment. This exercise illustrates the manner in which further experimental analysis of antigen-specific MBC subset distributions may be valuable; by understanding how imprinted memory is distributed across subsets and how vaccine formulations affect those subsets, it may be possible to design novel candidates and strategies that avoid activating imprinted subsets while eliciting the intended, protective de novo responses. Abbreviations: hCoV, human seasonal coronavirus; MBC, memory B cell; RBD, receptor-binding domain; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.