Conventional measurement of antibody responses to vaccines largely relies on serum
antibodies, which are primarily produced by bone marrow plasma cells and may not
represent the entire vaccine-induced B cell repertoire, including important functional
components such as those targeted to mucosal sites. After immunization or infection,
activated B cells differentiate into plasmablasts in local lymphoid organs, then traffic through
circulation to the target sites where they further develop into plasma cells. On day 7 after …