POZ Examines PrEP as HIV Prevention MethodPOZ in its June issue examined pre-exposure prophylaxis, the practice of HIV-negative people taking antiretroviral drugs before potential exposure to the virus, as a method of HIV prevention. According to POZ, PrEP "seems to present one of the most promising fronts in prevention research," but it is unclear whether the practice would be effective in preventing HIV among high-risk groups, such as men who have sex with men, commercial sex workers and injection drug users. In addition, the "biggest barrier" to studying the effects of PrEP has been the "inevitable ethical dilemmas involved in human PrEP trials, in which the placebo group must risk exposure to HIV to prove efficacy," POZ reports.
A 2005 CDC study found that 19% of respondents had heard of PrEP but only one-third of 1% had tried it to prevent HIV infection. CDC and NIH are conducting trials of PrEP among 5,000 people in Botswana, Ecuador, Peru and Thailand with results expected in 2008 and 2009. A Ghana trial conducted in 2006 by Family Health International, with funding from the Bill & Melinda Gates Foundation, among 900 HIV-negative sex workers is the only PrEP trial to have reached completion. According to POZ, too few new HIV cases occurred to conclude whether PrEP was effective in preventing transmission. CDC is planning to conduct a trial among 400 MSM in Atlanta, Boston and San Francisco to determine whether antiretrovirals are safe for daily use among HIV-negative people and whether taking the drugs brings a "false sense of security" that leads to high-risk behavior, POZ reports.
According to POZ, more research is needed to determine how many HIV cases could be prevented with PrEP and whether the strategy would be cost-effective to implement. In addition, research into the potential side effects of long-term antiretroviral use and possible psychological effects of using such drugs among HIV-negative people, as well as whether people would stop using condoms, is needed to determine whether PrEP would be an effective prevention tool in the U.S., POZ reports (Graham-Silverman, POZ, June 2007). This is part of the KHN Morning Briefing, a summary of health policy coverage from major news organizations. Sign up for an email subscription.