AIDS: A new National Institute of Allergy and Infectious Disease (NIAID)-sponsored HIV vaccine study will determine if combining two experimental HIV vaccines can stimulate the immune system to fight HIV. The two vaccines, vCP205 and rgp120, are genetically engineered and do not contain HIV; rather, the former contains four of HIV's nine genes, and the latter contains one recombinant HIV protein. Since no whole HIV is present, the vaccine cannot cause HIV infection. Four hundred twenty volunteers will be enrolled from fourteen sites nationwide. Volunteers will be randomized to one of three groups, those receiving both vaccines, or vCP205 and placebo, or two placebos. Eligibility criteria, contact phone numbers, and web sites are provided.