Analysis of intercurrent human immunodeficiency virus type 1 infections in phase I and II trials of candidate AIDS vaccines

Among 2099 uninfected subjects in phase I and II trials of candidate AIDS vaccines, 23 were diagnosed with intercurrent human immunodeficiency virus type 1 (HIV-1) infection, High-risk sexual exposures accounted for 17 infections, and intravenous drug use accounted for 6, Four subjects received placebo, 13 received a complete immunization schedule (greater than or equal to 3 injections), and 6 were partially immunized (less than or equal to 2 injections), There was no significant difference between vaccine recipients and control groups in incidence of HIV-1 infection, virus load, CD4 lymphocyte count, or V3 loop amino acid sequence, In summary, 19 vaccinated subjects acquired HIV 1 infection during phase I and II trials, indicating that immunization with the products described is < 100% effective in preventing or rapidly clearing infection, Laboratory analysis suggested that vaccine-induced immune responses did not significantly affect the genotypic or phenotypic characteristics of transmitted virus or the early clinical course of HIV-1 infection.