Disclosed herein is a recombinant Chlamydia-activated B cell (CAB) platform, vaccines, and methods of using the same. Disclosed is a method of enhancing a population of B cells, comprising exposing said B cells to a recombinant polypeptide derived from a Chlamydia spp.under conditions suitable to enhance the population of B cells, such that expansion and differentiation of said B cells takes place, and said B cells are exposed or crosslinked to an antigen. Also disclosed are methods to use a recombinant polypeptide derived from a Chlamydia spp.as an adjuvant for induction of enhanced humoral immunity against an unrelated antigen (e.g., humoral immunity against HIV antigen). Also disclosed are methods of producing said CABs, and treating a subject in need thereof with said CABs.
