What is PrEP for HIV Prevention? PrEP refers to an experimental HIV prevention strategy that proposes using antiretrovirals (ARVs) to reduce the risk of HIV infection in healthy uninfected people at risk for acquiring the virus. In this intervention, individuals would take a single drug or a combination of drugs orally (or via a topical microbicide) with the hope that it would lower the risk of infection if exposed to HIV. There are two ARVs currently being tested in PrEP human safety and efficacy trials: tenofovir (TDF) and a combination of tenofovir and emtricitabine (FTC). Scientists have focused on these drugs because they can be conveniently taken orally once a day, may have relatively low rates of minor side effects compared to benefit when used as prevention, and because there is significant data on their long-term safety and resistance profiles in HIV positive people.
PrEP clinical trials are currently planned or underway in countries in Africa, Asia, Latin America and North America. Taken together, these trials are designed to answer questions about how PrEP works in different parts of the world, and in individuals who are exposed to HIV through anal, vaginal and intravenous routes. There are more than 17,000 volunteers participating in PrEP trials worldwide. These trials have enrolled people with different types of behaviors that might put them at risk for HIV, including injection drug use and unprotected anal or vaginal sex. It’s important to learn how PrEP works in the context of different routes of exposure (for example via injection, anal or vaginal sex.)
PrEP Investment Global public-sector and philanthropic investment in pre-exposure prophylaxis (PrEP) over the last seven years totaled US$119 million. There are currently seven ongoing or planned PrEP trials of tenofovir-disoproxil fumarate (TDF) or of TDF combined with emtricitabine (TDF/FTC). In 2008, funding for PrEP was US$4.3 million greater than in 2007. This total does not include prevention of vertical transmission through ARV treatment, which can be considered PrEP.
