Quantitative analysis of influenza virus-specific B cell memory generated by different routes of inactivated virus vaccination

We consider both Ab-secreting cell (ASC) and memory B cell (BMem) populations in a quantitative analysis of virus-specific B cell memory generated by intramuscular or intranasal vaccination of mice with inactivated influenza virus. After both forms of vaccination, the memory phase was characterized by localization of ASCs in the bone marrow and dispersion of BMem to organized lymphoid tissues. The stronger IgG response to intramuscular vaccination correlated with larger numbers of IgG ASCs in the bone marrow and IgG BMem. IgA production was only prominent in the response to intranasal vaccination and was associated with IgA ASC localization in the lung and IgA BMem formation. Notably, few IgG ASCs or BMem localized in the lung after intramuscular vaccination, in contrast to the situation following influenza pneumonia. Our analysis links the nature of immunization to characteristics of the state of B cell memory that may relate to protective immunity.