Last year, a vaginal gel that reduced HIV infections in women was already considered a breakthrough. Now, a study published in Cell Hosts and Microbes suggests that the same drug could help protect against herpes, as well. Here, a guide to this unexpected development:  

What does the gel do?
Its active ingredient, tenovir, is a microbicide originally developed to combat AIDS in Africa. It can lower a woman's risk of HIV infection by 39 percent. Taken as a pill, it doesn't offer protection against herpes. But in gel form, the concentration of the drug is 100 times higher in the vaginal wall, where "tenorvir disrupts an enzyme that herpes uses to make copies of itself," says Margaret Hartmann at Jezebel. It can be even more effective against herpes than against HIV, reducing infection by as much as 51 percent.

How important is this breakthrough?
The drug's "unexpected bonus" could be huge. Herpes isn't fatal, but it can be painful and ruin sexual pleasure. Plus, it causes blisters resembling cold sores that can be entry points for HIV, syphilis, and other dangerous pathogens. The CDC estimates that 21 percent of all sexually active women have the incurable disease, which can be passed along through mere skin-to-skin contact. "Protection that a woman can control is the holy grail in this field," says University of Washington herpes expert Dr. Jean Marrazzo, as quoted by The New York Times.

Will it be available in America?
Perhaps, but it would probably take years for the drug to come to market in the U.S. Such a "magic" gel would be worth the wait, says Hartmann; the fact that it can be "subtly applied" without a partner's knowledge "gives women control over herpes and HIV protection." That, she says, is "pretty exciting." 

Sources: ABC News, Jezebel, NY Times, Jezebel