Vaccine May Put Brakes on Common Infection

The first vaccine for genital herpes, a contagious infection affecting nearly one in five Americans, is under study in women. MCG is among sites in 28 states studying the vaccine in approximately 7,500 women age 18 to 30 who have not been exposed to herpes simplex type 2, the cause of the genital infection, or herpes simplex type 1, which causes common fever blisters.

“It’s very debilitating, not only physically, but emotionally,” said Dr. Daron G. Ferris, director of the MCG Gynecologic Cancer Prevention Center and a principal investigator. “We hope this vaccine can help women avoid this lifelong infection.”

Previous research, published in 2002 in the New England Journal of Medicine, showed the vaccine works best in women who have not been exposed to either herpes strain and that it is not effective in men.

Antiviral agents on the market suppress outbreaks of the virus but don’t stop disease transmission. “There is no cure for herpes,” Dr. Ferris said. “People do shed herpes asymptomatically, so even if they do not have an outbreak, they can share herpes, for example, in vaginal secretions or urine.”

And the infection can be deadly for babies, who are delivered by Caesarean section if the mother is known to have an active type 2 herpes infection.

The durable virus hibernates in the dorsal ganglion, an area of nerves in the back. Stress and sunlight are two triggers that send the virus down the nerve pathways to cause an eruption.

The first outbreak is typically the worst, starting with a burning, itching sensation followed by blisters on both sides of the genital region that rupture and form ulcerations that can last up to 10 days. Recurrences generally occur on one side of the body and last about a week. Outbreak frequency varies widely among individuals. “I have patients who have an outbreak just once a year or every other year but, unfortunately, they remain contagious,” Dr. Ferris said.

The vaccine uses a fragment of the herpes virus protein that prompts the body to mount an immune response to

herpes type 2 so it will eliminate the virus on sight. It will be given in a series of three shots to approximately half the study participants. The other half get hepatitis A vaccine, which works in a similar fashion and is approved by the Food and Drug Administration to prevent infection with this hepatitis type, common in Central and South America and much of Asia. The hepatitis A vaccine also is considered investigational for the purposes of this study because it is being given in three rather than the usual two doses.

Participants will be followed for about 20 months.

The Herpevac Trial for Women is a joint initiative of the National Institute of Allergy and Infectious Diseases and GlaxoSmithKline Biologicals.