A vaccine against the herpes-simplex-2 virus, which causes genital herpes, protects some women, provided they haven’t had a genital or oral herpes infection before.
The vaccine consists of a molecule patterned after a protein that sits on the surface of the herpes-2 virus and a natural immune boosting substance called 3-O-deacylated monophosphoryl lipid A, says Lawrence Stanberry of the University of Texas Medical Branch in Galveston.
He and his colleagues identified 2,714 people in five countries whose regular sex partners have genital herpes. About one-third of the volunteers had no sign of oral or genital herpes at the start of the study. The rest had antibodies to herpes-simplex-1 virus, which causes cold sores.
The researchers gave half the volunteers three vaccine injections over 6 months. The others got inert injections as a placebo.
Of women who had no herpes at the start of the 19-month study, 22 percent of those getting a placebo subsequently acquired a genital herpes infection. In contrast, only 12 percent of vaccinated women developed such an infection, the researchers report in the Nov. 21 New England Journal of Medicine.
Women who had had oral herpes before the study gained little protection from the vaccine. This suggests that oral herpes might interfere with the vaccine’s building a reservoir of immune cells and antibodies against genital herpes, Stanberry says.
The vaccine didn’t protect men, regardless of whether they had oral herpes. Vaccine-stimulated immune proteins and cells may be more potent against herpes viruses contracted on the vaginal lining than on the skin of the penis, Stanberry says.
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