Safety of and Immune Response to a New HIV Vaccine: HIV CTL MEP

Prime-boost vaccine strategies are aimed at inducing different types of immune responses and enhancing the overall immune response, a result that may not occur with a single type of vaccine. This trial will evaluate the safety and immunogenicity of an HIV multi-epitope peptide cytotoxic T lymphocyte (HIV CTL MEP) vaccine developed as part of a prime-boost strategy and designed to be administered in combination with an HIV DNA vaccine. The HIV CTL MEP vaccine is a mixture of four synthetic peptides, each containing one of three different HIV CTL epitopes derived from env or gag. The use of multiple conserved CTL epitopes will address the extraordinary diversity found among HIV strains. The vaccine is administered with RC529-SE, an analogue of monophosphoryl lipid A. The vaccine/adjuvant combination will be evaluated with or without coadministration of granulocyte-macrophage colony-stimulating factor (GM-CSF). Participants will be randomly assigned to receive either the vaccine with the RC529-SE adjuvant, the vaccine with both adjuvants (RC529-SE and GM-CSF), or a placebo. The vaccine, adjuvants, and placebo will all be given as an injection into the upper arm. Participants will have 11 study visits. Study visits will include a physical exam, medical interview, and blood and urine tests. Participants will receive an injection at three of these visits: study entry and Months 1 and 3. Participants will be followed for 1 year after the last injection.