Complete Protection from Repeated Vaginal Simian-Human Immunodeficiency Virus Exposures in Macaques by a Topical Gel Containing Tenofovir Alone or with Emtricitabine
Parikh, U. M., Dobard, C., Sharma, S., et al. Journal of Virology (2009), 83(20), pp. 10358–10365.
Safety and efficacy studies are needed before microbicides can be tested in humans. This trial assessed how well tenofovir (TVF) vaginal gel or TVF with emtricitabine (FTC) protected 17 macaques from simian HIV (SIV) infection over a period of 20 weeks. The gel was administered twice weekly; simian-human immunodeficiency virus was administered 30 minutes after the gel. Five of six macaques in the placebo arm and both in the control arm (no intervention) became infected with SIV in an average of 2.5 weeks. None of the six macaques assigned active gel (TVF alone or TVF+FTC) became infected over 20 weeks (40 total SIV exposures). Furthermore, there was no evidence of damage to vaginal mucosa with use of either active microbicide. Despite study limitations, the authors conclude that this study suggests TFV gel can be used before intercourse to protect women from SIV without the need for daily use.