Safety of and Immune Response to an HIV Preventive Vaccine (HIV-1 Gag DNA Alone or With IL-15 DNA) Given With or Without 2 Different Booster Vaccinations in HIV Uninfected Adults

The purpose of this study is to determine the safety of and immune response to an experimental HIV vaccine, HIV-1 gag DNA, with and without an IL-15 DNA adjuvant (at escalating doses of 100, 500, and 1500 mcg). This study will also test the safety of and immune response to the HIV-1 gag DNA vaccine plus IL-15 DNA adjuvant given with or without 2 other adjuvant-containing booster vaccines.

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. There are two parts to this study. Part A will last 12 months. In Part A, 48 participants will be randomly assigned to 1 of 4 groups in sequential order (dose escalation). All participants will receive 3 vaccinations. Group 1 will receive 3 vaccinations of the HIV-1 gag DNA vaccine or placebo. Group 2 will receive 3 vaccinations of either the HIV-1 gag DNA vaccine with a low dose of IL-15 adjuvant or a placebo. Group 3 will receive 3 vaccinations of either the HIV-1 gag vaccine with a medium dose of IL-15 adjuvant or a placebo. Group 4 will receive 3 vaccinations of either the HIV-1 gag vaccine with a high dose of IL-15 adjuvant or a placebo. Vaccinations will be given at Months 0, 1, and 3. There will be 11 study visits in Part A. A physical exam, pregnancy prevention counseling, medication history, and adverse event reporting will occur at most visits. Urine and blood collection will occur at some visits. Participants will also be asked to complete questionnaires at certain visits. Part B will last 15 months. In Part B, 72 participants will be randomly assigned to 1 of 2 groups. All Part B participants will receive 5 vaccinations. Group 5 will receive 5 vaccinations of either the HIV-1 gag vaccine plus IL-15 DNA or placebo; the vaccinations will occur at Months 0, 1, 3, 6, and 9. Group 7 will receive 3 vaccinations of the HIV-1 gag vaccine with a high dose of IL-15 adjuvant (maximum tolerated dose from Part A) followed by 2 vaccinations of the gag DNA vaccine with IL-12 DNA adjuvant. Some participants will receive placebo instead of this vaccine regimen. For Group 7, the HIV-1 gag vaccine with IL-15 adjuvant vaccinations will be given at Months 0, 1, and 3, and booster vaccinations will be given at Months 6 and 9. There will be 13 study visits in Part B. A physical exam, pregnancy prevention counseling, medication history, and adverse event reporting will occur at most visits. Urine and blood collection will occur at some visits. Participants will also be asked to complete questionnaires at certain visits.