UNAIDS strongly welcomes results from scientific trials presented at the 2015 Conference on Retroviruses and Opportunistic Infections (CROI), held in Seattle, United States of America. Two studies demonstrate that the antiretroviral medicines tenofovir and emtricitabine when used as pre-exposure prophylaxis (PrEP) are 86% effective in preventing new HIV infections among men who have sex with men.
A third study showed 96% efficacy in preventing new HIV infections when the HIV-negative person in a serodiscordant couple (where one partner is living with HIV and the other is not) had access to PrEP and the HIV-positive partner had access to antiretroviral therapy.
“These new results are a significant breakthrough in advancing efforts to provide effective HIV prevention options to men who have sex with men and to serodiscordant couples,” said Michel Sidibé, Executive Director of UNAIDS. “The results are timely and important and will advance global efforts to end the AIDS epidemic by 2030.”
The PROUD study in the United Kingdom enrolled more than 500 men who have sex with men at higher risk of HIV infection. Half of the participants were given a daily pill of tenofovir and emtricitabine, the other half were deferred for one year before starting PrEP. According to the results presented at CROI, the people taking a daily pill of tenofovir and emtricitabine were 86% less likely to become infected with HIV than the people in the deferred group.
Results presented by the organizers of the Franco-Canadian IPERGAY study also showed the significant efficacy of PrEP. In the IPERGAY study some 450 men who have sex with men at higher risk of HIV infection were enrolled in a trial in which half were asked to take four tablets of tenofovir and emtricitabine, two before and two after sexual intercourse; the other half were given a placebo. According to the results presented, the people in the group taking the active pill before and after sex were 86% less likely to become infected with HIV.
In both the studies the trials were modified to offer active antiretroviral medicines to all participants after interim analysis of the data showed a significantly positive effect.
The Partners PrEP Demonstration Project enrolled more than 1000 serodiscordant couples in Uganda and Kenya. The HIV-positive partner in each serodiscordant couple was offered antiretroviral therapy and the HIV-negative partner was offered PrEP. A computer simulation model calculated the efficacy of PrEP combined with early treatment to be 96%.
The Partners PrEP Demonstration Project suggests that the use of PrEP as a potential bridge in serodiscordant couples—used while the HIV-positive person commences treatment until such a time that the risk of transmitting the virus is minimized—is highly effective in reducing new HIV infections.
Another study in South Africa, the FACTS 001 trial, showed that despite moderate adherence, with 50–60% of sexual exposures happening in the presence of gel, the use of 1% tenofovir as a vaginal gel was not effective in preventing new HIV infections among young women at higher risk of HIV infection. Despite disappointing results the study does provide valuable information about the urgent need to find new and effective HIV prevention options that work for young women.
UNAIDS warmly congratulates the researchers on completing four major studies of HIV prevention approaches in the populations that are most in need of prevention. For men who have sex with men at higher risk of HIV infection and for serodiscordant couples, PrEP, offered as part of a package of HIV prevention measures, is a highly effective additional HIV prevention option.
To advance efforts to end the AIDS epidemic by 2030, UNAIDS stresses the continued need for a combination approach to HIV prevention that includes biomedical, behaviour change and structural approaches.
The Joint United Nations Programme on HIV/AIDS (UNAIDS) leads and inspires the world to achieve its shared vision of zero new HIV infections, zero discrimination and zero AIDS-related deaths. UNAIDS unites the efforts of 11 UN organizations—UNHCR, UNICEF, WFP, UNDP, UNFPA, UNODC, UN Women, ILO, UNESCO, WHO and the World Bank—and works closely with global and national partners to maximize results for the AIDS response.