The cream, being developed by Massachusetts-based Alnylam Pharmaceuticals Inc, protected mice from herpes simplex 2, the virus that causes genital herpes, Olenka Palliser of Harvard Medical School in Boston and Edmon Einstein College of Medicine in New York and colleagues reported. Herpes viruses head straight to nerve cells, where they stay latent for the life of an animal or person, often causing periodic outbreaks. Study Andras € Researchers say they have developed a cream that might prevent herpes infection for as long as a week -- a potentially big step in protecting women from the sexually transmitted infection. New cream disables herpes virus. Related viruses are herpes simplex 1, which. The cream uses a new kind of therapy called RNA interference to turn off genes that the virus uses to invade cells, the researchers reported on Wednesday. "A vaginal microbicide able to protect against HSV-2 transmission could contribute significantly to controlling sexually transmitted diseases," Palliser's team wrote in the journal Cell Host & Microbe.

The World Health Organization estimates that 536 million people worldwide are infected with genital herpes, a painful and incurable virus which is highly infectious and can kill newborns.