Provided are methods of generating an immune response to any of variousantigens including foreign antigens such as infectious agent antigens. Ingeneral, the method comprises administering an expression vector encoding atranscription unit encoding a secretable fusion protein, the fusion proteincontaining the foreign antigen and CD40 ligand and also administering theencoded fusion protein. In another approach, an immune response to the foreignantigen is elicited using the encoded fusion protein without administering thevector. The invention methods may be used to immunize an individual against aninfectious agent such as influenza virus. Methods of obtaining an immuneresponse in older individuals also is described.
