1. Developing vaccines
A preventive inoculation was tested in Thailand in 2009; those who received it were 31 percent less likely to contract HIV than a placebo group was. The study, financed mainly by the National Institutes of Health, gives researchers hope that a stronger vaccine could be developed in the next few years. "It gives us something to build from," says Carl Dieffenbach, Ph.D., director of the Division of AIDS at NIH.
The government supports early-stage research into so-called therapeutic vaccines — ones that would prevent people with HIV from developing full-blown AIDS.
2. Using HIV drugs as preventatives
HIV-negative, sexually active gay men who took a daily dose of the HIV drug cocktail Truvada (Tenofovir and emtricitabine) reduced their odds of contracting HIV by 44 percent, in clinical trials performed in six countries last year. But Truvada is licensed as only a treatment, not a prophylaxis. That means many insurance plans might not pay for HIV-negative people to buy it.
3. Making gels that kill the virus
A recent study of 900 women in South Africa showed that a vaginal gel made from the active drugs in Truvada reduced the odds of acquiring HIV by 39 percent, a boon to women whose partners refuse to wear condoms. Research continues into microbicides that are inexpensive enough to be used regularly by women in the developing world.
4. Encouraging male circumcision
Studies have shown that men in Africa who have had their foreskin removed are 60 percent less likely to get HIV, perhaps due to the thinness of the foreskin's protective keratin layer and the presence of vulnerable immune cells there. Public health scientists are trying to find ways to reach more men and encourage them to undergo the procedure.
5. Improving successful treatments
The most promising of the newest class of anti-HIV drugs, raltegravir (trade name: Isentress), attacks the disease by zapping a viral enzyme, which interrupts the virus's life cycle. Used in tandem with other drugs, raltegravir has proven effective at keeping the "viral load" — the amount of HIV in the bloodstream — to a minimum. Other drugs that are like it, part of a class called integrase inhibitors, are in the pipeline.