Failure of Zidovudine Prophylaxis after Accidental Exposure to HIV-1

Abstract

ON the basis of encouraging data from two studies in animals,^{1 , 2} the manufacturer of the antiretroviral nucleoside analogue zidovudine (formerly azido--thymidine [AZT]) has initiated a placebo-controlled trial to assess the chemoprophylactic efficacy of zidovudine after occupational or nosocomial exposure to the human immunodeficiency virus type 1 (HIV-1).^{3 , 4} It is unlikely, however, that this trial will be completed soon, given the relatively low risk of infection through occupational exposure.⁴ In anticipation of the results of the study, several programs of zidovudine chemoprophylaxis for health care workers who have been occupationally exposed to HIV-1 have been implemented.⁴ The aftermath of a tragic accident in our hospital reveals that even when it is begun very soon after exposure, treatment with zidovudine will not necessarily prevent HIV-1 infection.