The pGA2/JS2 DNA vaccine is part of a planned prime/boost regimen of a DNA vaccine prime followed by a modified vaccinia Ankara (MVA) vaccine boost. In studies in monkeys, a combination of a DNA vaccine and an MVA vaccine protected the monkeys against disease caused by a monkey virus similar to HIV. The current study is an initial investigation of the safety and immunogenicity of the DNA vaccine given alone. The pGA2/JS2 DNA vaccine expresses gag, protease, reverse transcriptase, env, tat, vpu, and rev.