Influenza-specific antibody-secreting cells and B cell memory in the murine lung after immunization with wild-type, cold-adapted variant and inactivated influenza viruses.

The development of regional B cell responses was studied in mice immunized intranasally with different influenza virus vaccines. The ca-variant virus was 100-fold less efficient than the parental virus in the induction of influenza virus-specific antibody secreting cells (ASCs) in the lung and failed to induce ASCs in the spleen. The ca-variant virus was also less efficient in priming for secondary IgG and IgA responses generated in vitro in both lung and spleen cell cultures. Protection against homotypic challenge in mice immunized by different vaccine strategies correlated with the development of pulmonary B cell responses rather than splenic responses. In particular, protection correlated with the presence of ASCs and IgG and IgA memory in the lung at the time of challenge.