“A daily dose of powerful anti-HIV medicine helped cut the risk of infection with the AIDS virus by 49 percent in intravenous drug users [IDUs] in a Bangkok study that showed for the first time such a preventive step can work in this high-risk population,” Reuters reports (Steenhuysen, 6/13). “Earlier clinical trials showed that the therapy can sharply reduce the risk of HIV transmission from mother to child, and in gay and bisexual men and heterosexuals,” the New York Times writes (McNeil, 6/12). “The research by the CDC and the Thailand government was published online Wednesday by the journal Lancet,” the Associated Press notes, adding, “Based on the findings, the CDC recommended that doctors consider prescribing [the antiretroviral] tenofovir to those who inject drugs” (Stobbe, 6/12).

The researchers “recruited 2,411 volunteers who were attending drug-treatment clinics in Bangkok,” according to Agence France-Presse. At the end of four years, an “average reduction in infection risk of 48.9 percent [was seen] among tenofovir takers. But it rose to more than 70 percent among those who adhered most closely to the daily pill-taking,” AFP writes, noting, “The probe found no evidence of viral resistance nor of any serious side effects from taking tenofovir” (6/12). “Previous studies have shown [the prevention method, called pre-exposure prophylaxis, or PrEP,] can help reduce the risk of HIV infection by 44 percent in gay and bisexual men, and by as much as 75 percent in heterosexual couples in which one member is infected,” Bloomberg Businessweek adds (Bennett, 6/12). According to Jonathan Mermin, director of the CDC’s Division of HIV/AIDS Prevention, “[q]uestions to be addressed include how willing uninfected people would be to take a daily pill outside the confines of a clinical trial, how the cost would be covered and where they should get it — a primary-care clinic, a clinic specializing in HIV treatment or another setting,” the Wall Street Journal writes (McKay, 6/12).