A new Phase 2b clinical trial will study the effectiveness of antiretroviral vaginal gels and oral tablets in preventing HIV infection in women.

The Vaginal and Oral Interventions to Control the Epidemic (VOICE) study will test the safety and efficacy of two different HIV prevention methods. The gel contains Viread (tenofovir), and the oral tablets contain Viread or Truvada (emtricitabine/tenofovir).

For the first time, participants will be able to apply the gel at any time throughout the day. This makes the gel easier to use and offers greater privacy than previous gels, which had to be applied before sexual intercourse. The tablets will be taken once daily prior to exposure, a strategic approach known as pre-exposure prophylaxis (PrEP).

The goal of these approaches is to give women self-protection methods they can control. This is crucial in situations where it is difficult or impossible for women to refuse sex or negotiate condom use with their male partners.

“We need multiple, scientifically proven HIV prevention strategies acceptable to different populations to effectively combat the spread of the virus,” said Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID) in a press release about the trial.

More than 5,000 uninfected women aged 18-24 at risk for acquiring HIV will participate in the study. The trial will take place in 14 sites in South Africa, Uganda, Zimbabwe, and Zambia and will last for three and a half years.

NIAID is funding the trial with support from the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institute of Mental Health, as well as Gilead Sciences Inc. and CONRAD.

A companion study will examine day-to-day factors associated with adherence to the VOICE study pill or gel regimen. Another will study the potential effects of oral Viread on bone density in HIV-uninfected women.

For more information, please visit the NIAID Web site or the ClinicalTrials.gov Web site.