AEGiS-14IAC: Post-exposure prophylaxis among HIV-uninfected participants in a phase III HIV vaccine efficacy trial.

14th International AIDS Conference

Barcelona, Spain - July 7-12, 2002

Post-exposure prophylaxis among HIV-uninfected participants in a phase III HIV vaccine efficacy trial.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. WePpD2105)

Ackers ML, Buchbinder S, McKirnan D, Mayer KH, Novak R, Harro C, Popovic V, Heyward W, Para M, Fuchs J, Tabet S; Centers for Disease Control and Prevention, Atlanta, United States

BACKGROUND: HIV-uninfected participants in the AIDSVAX é « B/B phase III HIV vaccine efficacy trial may use antiretrovirals obtained from other sources for post-exposure prophylaxis (PEP). The frequency of PEP use and its impact on HIV incidence and risk behavior within an efficacy trial are unknown.

METHODS: Men who have sex with men (94%) and high-risk heterosexual women (6%) were enrolled at 61 clinical sites in North America and Europe into the 36-month vaccine efficacy trial. All participants provided concomitant medication data, including PEP use, at 6-month intervals. Supplemental data on PEP knowledge, perceptions, and use were obtained from trial participants at six sites.

RESULTS: Overall, 108 (2%) of 5418 participants reported PEP use. These 108 participants were from 36 trial sites in 27 US cities, Puerto Rico, 3 Canadian cities, and the Netherlands. In multivariate analysis, significant predictors (p≤ 0.05) of PEP use included California site enrollment (n=7 sites) (Odds ratio [OR]=3.2), age < 32 years (OR=2.4), having a known HIV-positive sex partner (OR=2.0), higher education level (OR=1.4) and greater recreational drug use (OR=1.2). Analysis of the supplemental PEP data from the six sites revealed 260 (46%) of 560 participants had heard of PEP, and trial PEP-users were more likely to believe PEP prevents HIV infection than were non-PEP users (81% vs. 59%; p=0.05).

CONCLUSIONS: Trial PEP use was limited and does not appear to have an impact on the conduct of this vaccine efficacy trial. As knowledge of and access to PEP expands, its use among trial participants may increase and affect HIV incidence and risk behavior in future HIV vaccine efficacy trials.

Keywords: AEGIS, AIDS Vaccines, HIV Infections, Clinical Trials, HIV Seropositivity, Risk-Taking, Incidence, Sexual Partners, Puerto Rico, North America, California, Europe, Canada, Netherlands, AIDSVAX, Human, Male, Female, prevention & control, therapy

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WePpD2105