Participants in Group 1 Treatment will receive p24CE1/2 pDNA and IL-12 pDNA at Day 0 and Month 1, then p24CE1/2 pDNA plus p55^gag pDNA and IL-12 pDNA at Months 3 and 6. Participants in Group 1 Control will receive placebo (sodium chloride for injection) at Day 0 and Months 1, 3, and 6.