Postexposure Prophylaxis with Zidovudine Suppresses Human Immunodeficiency Virus Type 1 Infection in SCID-hu Mice in a Time-Dependent Manner

Abstract

Occupational exposure to the human immunodeficiency virus(HIV)has led to a low but finite incidence of infection among health care providers. In such circumstances, post exposure administration of 3′-azido-3′-deoxythymidine (zidovudine; AZT) mightbe beneficial. Totest this possibility, the SCID-hu mouse(the immunodeficient C.B-17 scid/scid mouse engrafted with human hematolymphoid organs) was treated with AZT at different times after intravenous infection with a standard doseofHIV (knownto infect 100% of animals). If givenwithin 2 h, AZT suppressed infection in all animals; if givenafter 2 days, no suppressionwasobserved. At least in someanimals, an AZT-sensitive phaselasted foras longas 36h. Thesedata support the hypothesis that prompt administration ofAZT might be efficacious in suppressingacute HIV infection in humans. Further studies in the SCID-hu mouse might provide insight into treatment protocols of even greater efficacy.