PrEP Strategies Remain Valuable Prevention Tool, says AVACNEW YORK, March 4, 2013 /PRNewswire-USNewswire/ -- Results from a large-scale HIV prevention trial among African women known as VOICE (Vaginal and Oral Interventions to Control the Epidemic) provide an urgent reminder that products must meet the needs of the people using them. While disappointing, the results lend new urgency and direction to the search for additional safe and effective HIV prevention options for women, AVAC said today. Researchers announced today that none of three pre-exposure prophylaxis (PrEP) and microbicide interventions tested in VOICE – daily oral tenofovir, daily oral TDF/FTC (Truvada), and daily 1% vaginal tenofovir gel – provided additional protection against HIV in the study, likely because few of the women in the trial used the products as directed. This low adherence explains the lack of benefit and is consistent with data from other antiretroviral (ARV)-based prevention trials that found a correlation between higher levels of adherence and protection from HIV. The new results were presented in Atlanta at the 20 th Conference on Retroviruses and Opportunistic Infections (CROI). "The VOICE results reinforce what we already know from previous trials – these interventions work when they are used, and they don't work when they are not used," said Mitchell Warren, AVAC Executive Director. "PrEP is still a valuable option for many women, and men, who recognize their risk and can take PrEP consistently. Now we have a dual responsibility to understand who might benefit from daily PrEP and ensure that they can access it, and to accelerate the development of additional options that can meet the urgent needs of others." A range of trials has shown varying levels of effectiveness of tenofovir-based prevention for heterosexual men and women, and for men and transgender women who have sex with men. The VOICE data do not invalidate the prior trial results, including the finding that daily oral tenofovir-based PrEP provided high levels of protection for women in stable relationships where one partner was HIV-positive, and that 1% vaginal tenofovir gel was modestly effective on a different dosing schedule.