A trial of 8,323 women revealed that a vaccine designed to prevent genital herpes was only able to partially protect women from one strain of the virus, according to research published in The New England Journal of Medicine.
The vaccine, called HerpeVac, looked promising when previously studied in women who had a partner with the disease. In two previous trials, the vaccine demonstrated 73% and 74% efficacy against genital disease in women who were negative for both types of antibodies. The shot wasn't able to protect the men in those studies from the disease.
The findings didn't hold in this larger trial designed to mimic the general population. Subjects aged 18 to 30 years were given three doses of the vaccine over the course of 6 months. Researchers found that the vaccine was 58% effective against herpes simplex-1 (HSV-1), but not at all effective in preventing herpes simplex-2 (HSV-2). Overall, HerpeVac was just 20% efficacious in preventing genital herpes disease.
"I think this is the end of the vaccine," study co-author Dr. Peter Leone, an infectious disease specialist at the University of North Carolina, Chapel Hill, told MSNBC. "It would be difficult to imagine marketing a vaccine that would only work against HSV1."
The Phase III study was sponsored by GlaxoSmithKline ($GSK) and National Institute of Allergy and Infectious Disease.