AN ANIMAL-MODEL FOR ANTILENTIVIRAL THERAPY - EFFECT OF ZIDOVUDINE ON VIRAL LOAD DURING ACUTE INFECTION AFTER EXPOSURE OF MACAQUES TO SIMIANIMMUNODEFICIENCY VIRUS

We analyzed the kinetics of the virological and immunological events t hat occurred in four AZT-treated cynomolgus macaques during the acute infection that followed their exposure to the simian immunodeficiency virus (SIVmac251) grown on monkey PBMCs in a cell-free stock solution. These events included changes in the CD4(+) and CD8(+) T lymphocyte s ubsets, p27 antigenemia, infectious serum virus, and cell-associated v irus loads. The kinetics of these changes proved strikingly similar to those reported in human HIV-1 infection. Four other SIV-exposed macaq ues were treated with placebo instead of AZT. We demonstrated that AZT does not prevent SIV infection, even when administered before SIV ino culation. However, the peaks of p27 antigenemia and of serum and cellu lar viremia were significantly smaller and occurred significantly late r in the monkeys given AZT than in those given placebo.