Dose-ranging Study to Evaluate the Safety & Immunogenicity of a HIV Vaccine 732461 in Healthy HIV Seronegative Volunteers

This is a single center, observer-blind, randomized, dose-escalating, staggered study with 6 groups: 3 groups of 50 subjects receiving the adjuvanted candidate vaccine, at 3 different doses and 3 groups of 10 subjects receiving the non-adjuvanted candidate vaccine in water for injection, at 3 different doses. The vaccination schedule will be 0-1 month. Blood samples will be collected at 8 visits. The duration of the study will be approximately 14 months for each subject. Rationale for Protocol Posting Amendment: The third vaccination will be cancelled and the visit at Month 7 will be postponed to Month 9. The Protocol Posting has also been updated in order to comply with the FDA Amendment Act, Sep 2007.