The present invention is directed to novel pharmaceutical compositions and methods of inhibiting or blocking one or more virulence antigenic factors of multiple strains of Bacillus anthracis in an individual. Specifically, it involves the administering of an expression vector alone or in conjunction with a fusion protein. The expression vector has a transcription unit encoding a fusion protein composed of an antigenic factor of Bacillus anthracis or fragment thereof attached via a linker to the aminoterminal end of the CD40 ligand. This fusion protein has the ability to generate antibodies and/or cytotoxic T cells which inhibit or block Bacillus anthracis infection in an individual.