Combined immunization of HIV-2 group antigen gene recombinant vaccines inflict higher immune response

Objective: To obtain an effective immunization strategy by different types of HIV-2 gag recombinant vaccines against HIV-2. Methods: BALB/c mice were inoculated muscularly with HIV-2 gag recombinant DNA vaccine, or recombinant fowlpox virus, or both. Serum anti-HIV-2 antibody, spleen CD4⁺ and CD8⁺ T-cell counts and HIV-2-specific target-killing activity of spleen CTL in immunized mice were analyzed by ELISA, FACS and LDH release assay, respectively. Results: Serum HIV-2 specific antibody level and numbers of spleen CD4⁺ and CD8⁺ T-lymphocyte subgroups were detected higher by combined immunization than those of single immunizations, and HIV-2-specific target-killing activity of spleen CTL was stronger in combined immunization group. Conclusion: The strategy of priming with the recombinant DNA vaccine and boosting with the recombinant fowlpox virus shows a stronger specific cellular and humoral immune responses in mice.