Although recent advances have been made in antiviral therapy for AIDS, there is no cure for HIV-1 infection or AIDS, and drug therapy is too expensive for most affected populations. The development of safe, effective vaccines to prevent HIV-1 infection and AIDS worldwide is a global priority. One promising approach in the development of HIV-1 vaccines utilizes live vaccines as vectors to express HIV-1 antigens. The potential advantages of the live vector approach include the ability of live vector recombinants to induce long-lasting humoral and cell-mediated immunity (particularly neutralizing antibody and CD8+ cytotoxic T-cell activity) and the relatively low cost of production. Moreover, live vector recombinant vaccines administered orally might be able to stimulate the production of secretory IgA vaccine-specific antibodies locally at relevant mucosal sites.