Humoral immune responses of the donor mice immunized with HCV immunogens as determined by ELISA. Seven mice were immunized with HCV immunogens containing HCV plasmid DNA, HCV recombinant polyprotein and montanide. Mice were immunized three times intramuscularly and boosted twice with the same vaccine. After the third immunization, serum samples were collected, serially diluted and tested for reactivity with HCV core, E1 and E2 protein. Sera were collected from the mice pre-immunization were used as a baseline. Immunized mice had significant increase in total IgG, IgG1, and IgG2a after the third immunization at 1:900 antibody titer (* P < 0.05).