A new external vaginal treatment works to protect against genital herpes infection for as long as a week, a new study has found.
The topical microbicide works by "silencing" two genes, and was shown effective in mice, the study released Wednesday by Albert Einstein College of Medicine of Yeshiva University and Harvard Medical School found.
The treatment backed by Alnylam Pharmaceuticals Inc. protected mice from simplex 2, which causes genital herpes, according to Dr Deborah Palliser of Harvard University in Cambridge, Massachusetts, one of the study's co-authors.
Their results were published in the January 22 issue of Cell Host and Microbe.
Harvard Medical School professor of pediatrics Judy Lieberman, also a senior investigator at the Immune Disease Institute, oversaw development of the treatment.
Her team used a lab technique called RNA interference, or RNAi, the treatment cripples the virus in a molecular double hit: it disables its ability to replicate, as well as the host cell's ability to take up the virus.
"People have been trying to make a topical agent that can prevent transmission, a microbicide, for many years," Lieberman said. "But one of the main obstacles for this is compliance. One of the attractive features of the compound we developed is that it creates in the tissue a state that's resistant to infection, even if applied up to a week before sexual exposure. This aspect has a real practicality to it. If we can reproduce these results in people, this could have a powerful impact on preventing transmission."
And that also could help in reducing HIV transmission, the authors noted, as herpes sores can help ease HIV transmission.
Some 536 million people worldwide are infected with herpes simplex virus type 2 (HSV-2), the most common strain of this sexually transmitted disease, World Health Organization data show.
Infection rates are strikingly high in the United States, with an estimated one in five US adults infected with HSV-2.