Assessing per-sex-act HIV-1 risk reduction among women using the Dapivirine Vaginal Ring

Document Type

Article (peer-reviewed)

Publication Date

4-15-2024

Abstract

Background: Confounding introduced by individuals’ sexual risk behavior is potentially a significant source of bias in HIV-1 prevention intervention studies. To more completely account for sexual behaviors when assessing the efficacy of the monthly dapivirine ring, a new longer-acting HIV-1 prevention option for women, we estimated per-sex-act risk reduction associated with product use. Methods: We conducted a secondary analysis of data from MTN-020/ASPIRE, a phase 3, randomized, placebo-controlled efficacy trial of the dapivirine ring that recruited HIV-uninfected, African women aged 18–45 years. With cumulative sex acts as the time scale, we used multivariable Cox regression with inverse probability of censoring weights to estimate HIV-1 risk reduction associated with a rate of dapivirine release indicative of consistent product use. Results: Women in the dapivirine ring group (n = 1187) had an estimated incidence rate of 2.3 (95% confidence interval [CI], 1.8–3.1) HIV-1 acquisition events per 10 000 sex acts versus 3.6 (95% CI, 2.9–4.4) per 10 000 acts in the placebo group (n = 1187). Dapivirine release indicative of consistent ring use was associated with a 63% (95% CI, 33%–80%) per-sex-act HIV-1 risk reduction. Conclusions: These results support the efficacy of the dapivirine vaginal ring for HIV-1 prevention and help to inform decision-making for women, providers, and policymakers regarding product use.

The dapivirine vaginal rings used in this study were developed and supplied by the International Partnership for Microbicides (IPM).

DOI

10.1093/infdis/jiad550

Language

English

Project

The Dapivirine Vaginal Ring for HIV Prevention; International Partnership for Microbicides (IPM)

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