An experimental Herpes Vaccine protected young women against only one of the two types of sexually transmitted virus, dashing hopes for widespread use of the treatment.
Herpes Simplex Virus type 1 is known as HSV1 and Herpes Simplex Virus type 2 is known as HSV2. The study conducted on more than 8,000 women aged 18 to 30 found that the vaccine protected against HSV1, but not HSV2. They have not been able to find out the reason for failure in protection against HSV2. Still, Leone and his fellow investigators called the vaccine against HSV1 “a substantial step forward” in the quest for a future vaccine to protect against both types of herpes.
That’s important because many people still think that HSV1 causes only cold sores. “It used to be HSV1 above the waist, whereas HSV2 below the waist,” Leone said.
According to the Centers for Disease Control and Prevention, one in six Americans, aged between 14 and 49 years is infected with HSV2. Federal Health figures show that nearly 60 percent of adults in the U.S. are infected with HSV1.
In his study, though, HSV1 was a more common cause of genital disease in the women who didn’t get the herpes vaccine than HSV2. Scientists have assumed that people have to engage in oral sex to get genital HSV1 disease, Leone says, but his study didn’t find an association.
Women who weren’t infected with herpes at the beginning of the study were randomly assigned to receive either three shots of the herpes vaccine or three shots of the hepatitis A vaccine.
Two previous studies of the vaccine involved heterosexual couples in which either the man or woman was infected with herpes. The study found that the vaccine protected against both types of herpes in women, but neither of the types in men.
Leone and his fellow researchers said that perhaps having regular sex with an infected man primed the women’s immune systems to fight HSV1 and HSV2, or maybe they were naturally resistant. Leone further said that it might not have worked for men because the skin covering the penis is different from the membranes lining the vagina and cervix.
The trial conducted by Leone used a vaccine containing an HSV protein designed to trigger an immune response against the virus. Maybe, he said, a vaccine that uses weakened live virus – like the chickenpox vaccine – would work better.
Meanwhile, Leone said, many Americans live in fear of contracting herpes, saying you can transmit this and not know it terrifies people.”