WEDNESDAY, Jan. 4 (HealthDay News) -- A potential vaccine for genital herpes has shown without more limited effectiveness in thwarting one token of the sexually transmitted virus and in ~ degree ability to stop a second form from spreading, a new study shows.

A collection of American and Canadian researchers conducted a randomized hardship on more than 8,300 women aged 18 to 30 who tested negative by reason of both forms of the herpes simplex virus, known as HSV-1 and HSV-2. Half of the women were given the empiric vaccine while the other half were given the hepatitis A vaccine.

The founded on fact vaccine was 58 percent effective at preventing genital indisposition stemming from HSV-1, but completely ineffective against HSV-2.

"We were disappointed it did not convenient the primary [goal], which was palladium against all types of genital herpes," related study author Dr. Robert B. Belshe, a professor of medicament, pediatrics and molecular microbiology at Saint Louis University. "Herpes is a complicated organism and has ways of escaping the immune system, so we have to figure in a puzzle a way of overcoming those mechanisms."

The study is published Jan. 5 in the New England Journal of Medicine.

Genital herpes affects not far from 16 percent of Americans aged 14 to 49, according to the U.S. Centers for Disease Control and Prevention. Both types of the venom are released from their resulting sores mete can also be transmitted between outbreaks, and the pollution is potentially fatal in newborns who acquire it from their mothers for the time of birth.

Fifty clinical sites in the pair the United States and Canada followed the women -- who reported their be in possession of sexual risk behaviors -- between 2003 and 2007. A heightened hazard for HSV-1 infection was associated through six or more lifetime sexual partners and more than one partner in the preceding 12 months, while those who were 23 or older were not so much likely to contract HSV-1 than those between 18 and 22.

Factors not associated with an increased likelihood of HSV-1 included smack , condom use, oral sex, a chronicle of any sexually transmitted infection or to the end of time having a partner with herpes. Men weren't tried in this study, though prior examination showed investigational herpes vaccines to have ~ing ineffective in men and HSV-1 existing in fact women.

"I was very disappointed there wasn't more of a utility," said Dr. Bruce Hirsch, an attending cure in infectious diseases at North Shore University Hospital in Manhasset, N.Y., who wasn't involved in the study. "I compass we're asking that a vaccine yield better immunity than an actual virus provides. I'm concerned if we'll always find a vaccine effective for HSV-2."

"I deliberate what we tell patients is ... there are antiviral medications that can contribute a difference and can give vulgar herd comfort, and the availability of manipulation is encouraging," he added.

While other potential vaccines are in the pipeline, Belshe reported, the one that works probably needs to be "more complex" than the any recently studied, which contained a simple surface protein of the herpes venom. The chicken pox vaccine, which has been widely used in the by decade, is a good example of a herpes-of the same family virus that has been brought in a state of inferiority to control, he said.

"Something like that is what we need to come up by for HSV," he said. "I compass this is a very important study, and the end is an incredibly important step in figuring exhausted what will work."

More information

The U.S. Centers in favor of Disease Control and Prevention has besides on genital herpes.

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