December 24, 2010
MedPage Today examines recent HIV prevention developments, in a 2010 year in review piece, beginning with the announcement at the International AIDS Conference in July that a microbicide gel used by women before and after sex reduced HIV infection by 39 percent. "True, the so-called CAPRISA 004 trial was only a proof of concept, as the investigators admitted openly, and it will take considerably more study to bring a product to market," the news service writes. "But in the context of prevention efforts, the trial was a landmark, one of the high points in a 15-month span that brought -- for the first time ever -- nothing but good news," the story reports.
The article examines the history of challenges researchers studying strategies to prevent the spread of HIV/AIDS have faced, the discovery in 2009 that an experimental HIV vaccine cut the risk of becoming infected by HIV by 31 percent, and the announcement in November 2010 that "so-called pre-exposure prophylaxis" or PrEP with daily oral antiretroviral -- "a combination of tenofovir and emtricitabine (in a single pill sold as Truvada)" -- reduced risk of contracting HIV by 44 percent in men who have sex with men (MSM).
"Taken together, the three studies have re-energized the field," MedPage Today writes. "It's a bit of boom time for HIV prevention," said Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition. However, Warren noted, more trials are needed to verify the effectiveness of the products.
"Three trials are likely to report in 2011, all testing pre-exposure prophylaxis with tenofovir and emtricitabine in various populations in Africa. ... Interestingly, those studies may have the quickest clinical impact, if only because the combination pill, Truvada, is already on the market," the news service writes.
Researchers will also be closely watching a Partners PrEP study in Uganda and Kenya, expected to end in 2012 or 2013, to see whether "oral tenofovir or the combination of tenofovir and emtricitabine has any preventive effect on transmission" of HIV/AIDS in couples where one partner is infected with HIV/AIDS and the other is not. Another trial underway, known as VOICES, "is testing oral and topical prophylaxis" in nearly 5,000 women; the results of this trial are expected to come in 2012, according to MedPage Today.
The article describes additional efforts by researchers to monitor the efficacy of PrEP as well as the limitations of PrEP in preventing the spread of HIV/AIDS (Smith, 12/23).