The African country of Uganda is severely affected by HIV infection and AIDS and has been selected by the World Health Organization to participate in HIV-vaccine development. The predominant HIV-1 strains isolated from Ugandans are members of clade A and clade D. The only vaccines available for human testing are based on envelope proteins from clade B and clade E viruses. ALVAC-HIV vCP205 is a second generation vaccine that can induce a humoral and cellular response against several antigens. The current study will attempt to extend these findings to determine if the vCP205 vaccine, when administered to Ugandans, can induce cytotoxic T-lymphocyte (CTL) responses that are reactive against the HIV strains prevalent in Uganda.