The study was ultimately stopped in April by the National Institute of Allergy and Infectious Diseases—a branch of the National Institute of Health—marking the sixth efficacy trial for an HIV vaccine and the fifth negative result, with the only success to date coming from a 2009 study in Thailand.
The finding is the latest setback toward finding a means of eradicating a disease that affects more than 1.1 million in the U.S., according to estimates from the Centers for Disease Control and Prevention.
“I think there is hope even though it's a negative study,” said study co-author Dr. Scott Hammer, a professor of medicine at Columbia University's Department of Medicine. “We've learned from each of the trials.”
For example, Hammer noted, researchers were able to recruit 2,500 men who have sex with men and transgender people who have sex with men, traditionally difficult populations to reach for clinical trials.
Hammer said he hopes the trial will provide lessons to others on ways to successfully reach out to these groups. The recruitment effort involved newspaper advertisements, use of social media and sending staff members of the 21 trial sites into the communities to build trust among likely candidates.
The NIH-funded HIV Vaccine Trials Network, based in Seattle, was responsible for coordinating the recruiting campaign.
“It was a very active outreach program that engaged the affected populations as best we could,” Hammer said. “And I think the demographics of the population reflect that effort.” Of the trial participants, whose median age was 29, 70% were white, 16% were black, 8% were Hispanic and 1% were Asian.
Gay, bisexual and transgender men who have sex with men have long been identified as the group most affected by HIV. According to the CDC, in 2010 such groups accounted for 63% of all newly infected cases at 29,800, a 12% increase from 2009. African-Americans and Latinos are also disproportionately affected by HIV.
Overall, the rate of new cases of HIV has fallen around the world in recent years—down to 2.3 million in 2012 from 2.5 million in 2011—while in the U.S., the rate has remained stable between 40,000 and 50,000 new cases each year for nearly a decade.
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