Thanks to modern treatments, HIV, though incurable, is far from the death sentence it once was. But it is still a life sentence, coming with the high cost, both personal and economic, of chronic disease, making avoiding infection in the first place a major goal for public health agencies. To that end, after numerous trials, the FDA has now approved Truvada, a combination drug that is already being used to treat HIV, as a preventative. Truvada and its component drugs have made headlines in recent years as researchers tested them out in what they call "high-risk populations": the uninfected partners of people who have HIV, African women, and other groups that are at a higher risk than the general population for contracting the disease. Although condoms can help prevent HIV transmission, people don't always use them, and alternatives that can be applied or taken before sex, like gels and pills, may help these populations protect themselves. In one trial, Truvada reduced the risk of contracting HIV by 90% in gay men who took it religiously. In another, this one with 4,800 heterosexual couples in which one member had the disease, it reduced the rate of transmission by 75%.