The new “trivalent” vaccine targets three different parts of the virus, shutting down its ability to enter cells and to evade detection by the immune system, said senior researcher Dr. Harvey Friedman. He’s a professor with the University of Pennsylvania School of Medicine’s Institute for Immunology.
In lab studies, the vaccine proved 98 percent effective in protecting guinea pigs against genital herpes infection, Friedman and his colleagues reported.
The vaccine also promoted an immune response in monkeys, increasing the levels of antibodies targeting the virus, the study authors said.
The vaccine’s developers now are shopping it around to different pharmaceutical companies for further development and human testing, Friedman said.
Human trials could begin within 18 months if a business partner is found, he added. Results of animal studies often aren’t duplicated in humans, however.
Approximately 500 million people around the world are infected with the genital herpes virus, the researchers said in background notes. In the United States alone, an estimated one in six people aged 15 to 49 has genital herpes.
The virus is painful and embarrassing for adults, often producing blisters and sores in the genital area. But it also has profound health effects. Infants born to infected mothers can contract the virus, developing severe and often lethal illness.
Additionally, people with genital sores caused by herpes are much more susceptible to HIV infection, Friedman said.
“An effective genital herpes vaccine could have a major impact on the HIV epidemic,” Friedman said. The hunt for a herpes simplex virus 2 vaccine has been underway for about four decades, he added.
The virus is tricky to defeat. It can go dormant for long periods after infecting cells, avoiding detection by the immune system between herpes outbreaks, Friedman explained.
“This virus is well-adapted to living long-term in our bodies,” he said. “It has adapted strategies so that even if our immune system is intact, we can’t get rid of it.”