ANALYSIS OF INTERCURRENT HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 INFECTIONS IN PHASE-I AND PHASE-II TRIALS OF CANDIDATE AIDS VACCINES

Among 2099 uninfected subjects in phase I and II trials of candidate A IDS vaccines, 23 were diagnosed with intercurrent human immunodeficien cy virus type 1 (HIV-1) infection, High-risk sexual exposures accounte d for 17 infections, and intravenous drug use accounted for 6, Four su bjects received placebo, 13 received a complete immunization schedule (greater than or equal to 3 injections), and 6 were partially immunize d (less than or equal to 2 injections), There was no significant diffe rence between vaccine recipients and control groups in incidence of HI V-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 p roducts described is < 100% effective in preventing or rapidly clearin g infection, Laboratory analysis suggested that vaccine-induced immune responses did not significantly affect the genotypic or phenotypic ch aracteristics of transmitted virus or the early clinical course of HIV -1 infection.