The agency approved Gilead Sciences' pill Truvada as a preventive measure for people who are at high risk of acquiring HIV through sexual activity, such as those who have HIV-infected partners.
Public health advocates say the approval could help slow the spread of HIV, which has held steady at about 50,000 new infections per year for the last 15 years. An estimated 1.2 million Americans have HIV, which develops into AIDS unless treated with antiviral drugs. With an estimated 240,000 HIV carriers unaware of their status, doctors and patients say new methods are needed to fight the spread of the virus.