Researchers working with 600 people who use the HIV prevention pill Truvada have just revealed their striking results: after more than two-and-a-half years, no new HIV infections have been detected. The work was published in Clinical Infectious Diseases this week.
The daily pill Truvada is what’s known as an HIV pre-exposure prophylaxis (PrEP). Green-lit by the U.S. Food and Drug Administration in July 2012, it’s the first drug approved that reduces the risk of infection in uninfected individuals who may engage in sexual activity with HIV-infected partners. When the person is exposed to HIV, two anti-retroviral medicines (called tenofovir and emtricitabine) contained within the pill work to keep the virus from establishing a permanent infection when taken consistently, according to the Centers for Disease Control and Prevention.
Early on, the blue pill was criticized for encouraging unsafe sex because of a false sense of security, SFGate reports. However, a published study that looked at sexual risk compensation in those taking PrEP found this not to be the case, and in fact observed a trend towards safer sex.
For this study in San Francisco, a Kaiser Permanente team tracked 657 PrEP users, almost all of whom were gay or bisexual men, over the course of 32 months. Despite the high rates of sexually transmitted infections among the participants – as well as reports of risky behavior, such as injection drug use and decreased condom use – there were no new HIV infections among this study group. So they did contract STIs including chlamydia, gonorrhea, and syphilis, but not HIV.
“This is very reassuring data,” study leader Jonathan Volk of Kaiser Permanente San Francisco Medical Center told the New York Times. “It tells us that PrEP works even in a high-risk population.” It’s best combined with condoms and frequent STI-testing.
This is the first real-world study of Truvada, although observational studies aren’t typically considered as scientifically rigorous as randomized clinical trials that utilize control groups and placebos. Also, the researchers don’t know for sure if the participants took their pills regularly. “PrEP is another line of defense,” Volk said. “I don’t think PrEP is right for everybody. But for the folks who need it, it works,” he added in an interview with SF Gate.