Evaluating the Safety and Immunogenicity of Polyvalent DNA/gp120 HIV Vaccine in Healthy, HIV-uninfected Adults

The purpose of the study is to evaluate the safety, tolerability, and immunogenicity of polyvalent env (A,B,C,A/E)/gag (C) DNA and gp120 (A,B,C,A/E) protein vaccines (PDPHV201401) co-administered together with or without adjuvant in repeated doses in healthy, HIV-uninfected adults. Participants will be enrolled in either Group 1 or 2 with Group 1 being enrolled first to compensate for the longer duration of vaccination period. Within each group, participants will be randomly assigned to either Treatment or Control. Participants in Group 1 (Treatment) will receive polyvalent env (A,B,C,A/E)/gag (C) DNA vaccine in one arm and polyvalent gp120 (A,B,C,A/E) protein vaccine mixed with GLA-SE adjuvant in the other arm on Day 0 and at Months 3, 6, and 12. Participants in Group 1 (Control) will receive placebo on Day 0 and at Months 3, 6, and 12. Participants in Group 2 (Treatment) will receive a mixture of polyvalent env (A,B,C,A/E)/gag (C) DNA vaccine and polyvalent gp120 (A,B,C,A/E) protein vaccine (without GLA-SE adjuvant) divided into two doses and administered into each arm on Day 0 and at Months 1, 3, 6, and 8. Participants in Group 2 (Control) will receive placebo on Day 0 and at Months 1, 3, 6, and 8. Study visits for participants in Group 1 will occur on Day 0, Week 2, Months 3, 3.5, 6, 6.5, 12, 12 + 1 Week, 12.5, 18, and 24. Study visits for participants in Group 2 will occur on Day 0, Week 2, Months 1, 1.5, 3, 3.5, 6, 6.5, 8, 8 + 1 Week, 8.5, 14, and 20. Visits may include physical examination, blood and urine collection, HIV testing, risk reduction counseling, and questionnaires.