Research in The New England Journal of Medicine has shown that Truvada has the ability to effectively prevent the spread of HIV infection. But will it?
In April of 1984, three years after the Centers for Disease Control first announced a spate of rare, virulent infections among gay men in Los Angeles, Health and Human Services Secretary Margaret Heckler stood before a gaggle of Washington reporters and predicted that an AIDS vaccine would be soon in coming. She was hoping to quell the maelstrom of misinformation and fear that gripped the country as landlords evicted HIV-positive tenants, hemophilic children were banned from school, and San Francisco police officers donned masks and gloves while working beats in the Castro. Give it two years, Heckler assured the assembled cameras. "Yet another terrible disease is about to yield to patience, persistence, and outright genius."
Three decades later, despite a heroic and awful patience, the maladie terrible haunts us still. The statistics belie the years of effort and billions of dollars invested in the search for a cure: 1.2 million Americans live with HIV -- as many as in Uganda and Zimbabwe -- with up to 50,000 new infections in the United States each year. The gay and black communities are hardest hit, particularly in the Deep South, and at least one in five don't know their positive status. In Washington, D.C., where the 19th annual International AIDS Conference is to be held later this month, the known rate of HIV is triple what the World Health Organization considers "epidemic." You can't walk a block downtown without passing a coffee shop that offers free condoms or a bus stop ad reminding you that real men "ask for the test." But the message has been slow to gain traction.
Welcome, then, are a trio of studies in the New England Journal of Medicine demonstrating that Truvada, an anti-retroviral drug already on the market, can prevent new HIV infections when taken daily. The findings, which were released in part last year and appear this week in final form, offer hope for men and women -- gay and straight -- who are at high risk for contracting HIV from their partners. "What we're looking at here is a new HIV prevention strategy, an approach that hadn't been tested before," said Jared Baeten, an infectious diseases specialist at the University of Washington's School of Public Health. "By having the medication already in their blood stream and in their cells, by the time they came into contact with virus, it would block the virus from taking hold. It would block them from getting infected."
Baeten's study followed 4,700 "serodiscordant" couples -- in which one member was HIV-positive and the other negative -- in Kenya and Uganda. Previous research had shown the efficacy of Truvada in reducing the risk of the disease among men who have sex with men, and Baeten's team hoped to expand the data to heterosexual partners. In addition to receiving a daily drug -- either Truvada or a placebo -- the HIV-negative subjects received STI testing, AIDS awareness counseling, and access to condoms. At the end of the trial, men and women in the Truvada arm of the study were 75 percent less likely to contract HIV than their untreated counterparts. (That figure, while impressive, is even conservative. It included every subject who was given Truvada, regardless of whether they remembered to take it.)
Later, Baeten went back and isolated just those participants who actually took the drug, as evidenced by their blood work. Their level of protection? Ninety percent.
Bottom line, says Baeten: "Compliance with this medication is the key to it working." Missed doses may be forgiving for a day or two, but physicians aren't certain, and consider the drug safe enough -- side effects include nausea and dizziness, and in some cases a loss in bone density -- to give to otherwise healthy patients on a daily basis.