Need for HIV vaccine is greater than ever
Woodruff Health Sciences Center | May 18, 2012
Despite tremendous improvements in HIV treatment and a dramatic reduction in AIDS deaths from 55,000 to 16,000 annually, the U.S. and other countries are still falling behind in new infections.
"We need an HIV vaccine, says Emory University infectious diseases and vaccine expert Mark J. Mulligan. "Every year for 15 years, about 56,000 Americans have become newly HIV-infected. This number has not fallen despite behavioral education efforts."
In a disturbing calculus, says Mulligan, treatment success paired with prevention failure means the United States is adding 40,000 more people living with HIV each year. The global trend is similar: 900,000 more people are living with HIV each year. So a vaccine for HIV is a key missing prevention tool.
Earlier, candidate vaccines in four large clinical trials failed to prevent HIV infection or lower virus levels after infection. Then, in 2009, an HIV vaccine study of 16,000 heterosexual men and women in Thailand demonstrated — for the first time ever — a modest reduction (31 percent) in HIV infections in vaccinated people over a three-year follow-up period.
When the analysis was limited to the first year after vaccination, a 60 percent protection rate was observed, suggesting that a booster was needed.
"However encouraging these findings are, the hard truth is that we are still several years away from a widely available vaccine," Mulligan points out. "Sadly, that means millions more women and men will become HIV-infected before we have the vaccine we need."
|Mark J. Mulligan, a professor of medicine in the Division of Infectious Diseases at Emory University and co-director of the Clinical Core of the Emory Center for AIDS Research. Mulligan serves as executive director of the Hope Clinic of the Emory Vaccine Center.|
This month a panel of experts recommended that the FDA approve preventive use of the HIV medication Truvada, a combination of tenofovir and emtricitabine, in people who are HIV-negative but at high risk of infection. Emory scientists were the inventors of emtricitabine, which has helped transform treatment for infected individuals over the past decade. The FDA, which usually accepts such expert panel recommendations, will decide by mid-June on Truvada for prevention.
"The prevention pill could be a supplement to — but not a replacement for — condoms, counseling, and safer sex," says Mulligan. "If it is not taken daily, its effectiveness goes down. One barrier to broad uptake is the cost, $14,000 per year, and there's more we need to learn about its long-term side effects and the development of resistance."
Still, he notes, it is good to know that we may soon have a new FDA-approved HIV prevention tool for some truly high-risk people who can afford the drug and take it faithfully. "Ultimately, however, we still need a vaccine!"
Mulligan suggests participating in a vaccine clinical trial for uninfected people at the Hope Clinic.
"If you are not infected with HIV, this is a powerful way to — literally — roll up your sleeves, take a shot, and help fight HIV."
To learn more, visit www.hopetakesaction.org or call 877-424-HOPE.