Provided are methods of selecting domains of the dengue hemorrhagic fever virus E protein for generating a neutralizing antibody immune response to the dengue hemorrhagic fever virus. The method comprises priming an individual by administering a mixture of expression vectors encoding fusion proteins or the fusion proteins themselves which comprises the DHFV E antigen fragment linked to the extracellular domain of the CD40 ligand. The expression vector comprises a transcription unit encoding a secretable fusion protein, the fusion protein containing the DHFV E antigen fragment linked to the CD40 ligand. The methods may be used to immunize an individual against all four strains of dengue hemorrhagic fever virus.