This study will evaluate the safety and tolerability of AdC6-HIVgp140 and AdC7-HIVgp140 at doses of 1 x 10^10 virus particles (vp) and 5 x 10^10 vp, alone and in combination with CH505TF gp120 adjuvanted with GLA-SE in HIV- uninfected adults.~Participants will be randomly assigned to 6 groups, separated into low dose (Part A; Groups 1-3) and high dose (Part B; Groups 4-6).~Participants in Group 1 (Groups 1-3) will receive 1 x 10^10 vp of AdC6-HIVgp140. Participants in Group 2 will receive 1 x 10^10 vp of AdC7-HIVgp140. Participants in Group 3 will receive Placebo control.~Part A participants will undergo 6 months of scheduled clinic visits (main study) followed by AESI (Adverse Events of Special Interest) health contacts at month 12, and then annual health contacts at month 24 and 36.~Participants in Group 4 will receive 5 x 10^10 vp of AdC6-HIVgp140 followed by 5 x 10^10 vp of AdC7-HIVgp140 (month 3) and 400 mcg CH505TF with 10 mcg GLA-SE (month 6). Participants in Group 5 will receive 5 x 10^10 vp of AdC7-HIVgp140 followed by 5 x 10^10 vp of AdC6-HIVgp140 (month 3) and 400 mcg CH505TF with 10 mcg GLA-SE (month 6). Participants in Group 6 will receive Placebo control.~Part B participants (Group 4-6) will undergo 12 months of scheduled clinic visits (main study) followed by an AESI health contact at month 18, and then annual health contacts at month 24 and 36.
The purpose of this study is to evaluate the safety and immunogenicity of HIV-1 vaccines based on chimpanzee serotypes of adenovirus expressing clade C gp140 and a CH505TF gp120 protein boost in healthy, HIV- uninfected adult participants.