After the prescreening, volunteers will be randomized into Group I or Group II. Each group will contain 16 volunteers. At least 5 volunteers in each group must be women. At month 0 all volunteers will receive multivalent HIV-1 peptide immunogen or the placebo. Group I will receive the injection in the deltoid and Group II will receive it in the anterior thigh. At months 1, 2 and 8 all patients will receive microparticulate monovalent HIV-1 peptide or the placebo. Follow up will be conducted.