The primary objective of this study is to assess the safety and tolerability, as well as the ability, of a heterologous-insert prime-boost vaccine regimen using env inserts from different HIV-1 clades to increase T-cell responses. In addition, this study is evaluating the effectiveness of a heterologous-insert prime-boost and vector prime-boost vaccine regimen at increasing T-cell responses. The study will also compare the degree of polyfunctionality of insert specific T cells after vaccination within heterologous and homologous vector vaccine regimens.