Provided are methods of generating an immune response to an antigen. The method comprises priming an individual by administering an expression vector encoding the antigen. The vectors comprises a transcription unit encoding a secretable fusion protein, the fusion protein containing an antigen and CD40 ligand. Administration of a fusion protein containing the antigen and CD40 ligand is used to enhance the immune response above that obtained by vector administration alone. The invention methods may be used to generate an immune response against cancer expressing a tumor antigen such as a mucin or human papilloma viral tumor antigen and to generate an immune response against an infectious agent. Also provided is a method for simultaneously producing the expression vector and the fusion protein.