The virus that causes genital herpes is incredibly common—about 15 percent of Americans ages 14 to 49 carry it—and an effective vaccine has been hard to find.

That's because the herpes simplex virus-2—which also causes serious eye infections in babies and people with weak immune systems—spends so little time in our bloodstream, where most vaccines get to work. But researchers at University of Illinois at Chicago have seen a breakthrough (at least in mice studies) with a new approach that comes in the form of a topical cream.

Right now, people with genital herpes are limited to medications that will suppress the symptoms and decrease the number of flare-ups. The new study, published in the Journal of Immunology by UIC researchers and German scientists, shows that nanoparticles called ZOTEN are able to keep the virus from infecting cells and stimulate the immune system to fight the virus long-term.

"It possesses both microbicidal and vaccine-like properties," says Deepak Shukla, one of the researchers on the study. "It is a totally novel approach to developing a vaccine against herpes, and it could potentially also work for HIV and other viruses."

Shukla, a professor at the UIC College of Medicine, expects human studies of the vaccine to come in the future, but in the meantime, he and other researchers will continue testing on non-human subjects to improve the way ZOTEN works. (The nanoparticles were synthesized by material scientists in Germany.)

In the recent study, female mice swabbed with the virus and the ZOTEN cream had significantly fewer lesions and less central nervous system inflammation than mice that were swabbed with the virus and placebo cream. By watching the nanoparticles interact with the virus and immune system cells, Shukla says they were able to see how it helps facilitate immunity, too.

Traditional preventative approaches "have failed against genital herpes and HIV," Shukla says, which makes the success of this two-sided approach even more exciting for researchers. Though it's still in early research stages, if the cream can proceed to clinical studies and be proven effective on humans as well, it could change the way we look at a virus that affects millions of Americans.