A new study shows once again that giving people at high-risk for HIV an antiretroviral pill daily cuts their risk of contracting the virus dramatically. In this case, a study of 2,400 Thai drug users over a five-year period found that giving them a once-a-day dose of a tenofovir (marketed in the U.S. as Truvada) cut their chances of becoming HIV positive by 49%.
The study is just the latest in a strong line that shows that the treatment, known as pre-exposure prophylaxis, or PrEP, is a potentially potent weapon in the arsenal of HIV prevention. Previous studies were conducted among gay and bisexual men, heterosexuals, and mothers and children.
“This is an exciting day,” Dr. Jonathan Mermin, director of H.I.V. prevention for the Centers for Disease Control and Prevention in Atlanta told The New York Times. “This culminates a decade of PrEP research.”
The question now is: do pills now become a standard part of HIV prevention strategies? Given the outcomes of the PrEP studies, it’s hard to argue against tenofivir. But, as with all things HIV, the answer may not be that easy. Among the issues that have to be considered:
- How does PrEP fit with existing prevention tactics, like condoms and needle exchanges?
- How well will patients adhere to the once-a-day regimen?
- Will certain sub-populations be more open to a pill than others?
- Will the cost of treatment crowd out government spending on other prevention methods?
- How can providers ensure that patients don’t see tenofovir as a guarantee against infection?
One thing is clear: tenofovir opens new possibilities for HIV prevention. In that sense, the questions are a nice problem to have.