Pre-exposure use of HIV meds reduces risk of infection in HIV-negative people

New strategies to combat the spread of HIV/AIDS may soon be offered following the results of a study published in New England Journal of Medicine. The study revealed that pre-exposure use of HIV medications reduces the risk of infection in those who are HIV-negative. Boston's Fenway Institute was one of two U.S. sites involved in the study.

The study, called iPrEx, showed that individuals at high risk for HIV infection who took a single daily tablet containing two widely used HIV medications -- emtricitabine and tenofovir (FTC/TDF) -- experienced an average of 43.8 percent fewer HIV infections than those who were assigned to take a placebo pill. The study is the first evidence that pre-exposure prophylaxis (or PrEP) reduces the risk of HIV infection in people already at risk for infection.

"We had reached a plateau in preventing the transmission of HIV," said Dr. Kenneth Mayer, Medical Research Director and Co-Chair of The Fenway Institute and one of the Principal Investigators on the study and an author on the New England Journal of Medicine article.

"For more than 15 years, the rate of new infections in the U.S, has been stuck at about 56 thousand per year; globally, there are more than 2.5 million new HIV infections per year. There has been no downward movement in this number; which has meant that we desperately needed a new approach. Today's announcement marks a tremendous step forward -- it's now possible that within the next few years, we can significantly reduce the number of new infections."

A total of 2,499 gay and bisexual men, men who have sex with men (MSM), and transgender women at high risk of HIV infection participated in the study. All study participants received a comprehensive package of prevention services designed to reduce their risk of HIV infection throughout the trial, including HIV testing, intensive safer sex counseling, condoms, and treatment and care for sexually transmitted infections. Half of study participants also received the PrEP pill, while the other half received a placebo.

"iPrEx proves that PrEP provides important additional protection against HIV when offered with other prevention methods such as HIV testing, counseling, condom use, and management of sexually transmitted infections," said iPrEx Protocol Chair Robert Grant, MD, MPH of the Gladstone Institutes and the University of California at San Francisco. "As with other prevention methods, the greatest protection comes with consistent use. I hope this finding inspires a renewed commitment from communities, industry, and government to stop the spread of HIV."

For more information about the study and the Fenway Institute, please visit www.fenwayhealth.org.

UPDATE: President Barack Obama reacted to the news Nov. 23, saying, "I am encouraged by this announcement of groundbreaking research on HIV prevention. While more work is needed, these kinds of studies could mark the beginning of a new era in HIV prevention. As this research continues, the importance of using proven HIV prevention methods cannot be overstated."

View more study results here.