 The HIV epidemic is a major global health challenge, causing tremendous human suffering and economic loss throughout the world. The need for a safe, effective, and affordable HIV preventive vaccine is critical. This 2-part study will determine the safety and immunogenicity of the experimental HIV vaccine HIV-1 gag DNA with or without IL-15 adjuvant, boosted with either the HIV-1 gag DNA and IL-15 adjuvant vaccine or the HIV-1 gag DNA and IL-12 adjuvant vaccine. 