A vaccine based on a genetically modified strain of herpes simplex virus 2 - the type usually responsible for genital infections - rapidly induces an immune response in mice and guinea pigs, researchers report.

Dr. Stephen E. Straus of Harvard Medical School, Boston and colleagues developed the vaccine, dubbed dl5-29, in which they deleted genes from the virus so that it could not replicate. The researchers then compared the performance of this novel vaccine with that of another type of herpes vaccine (gD2), which has already been tested in humans.

In test animals, both dl15-29 and the gD2 vaccine were highly effective in reducing the severity of acute herpes infections and recurrent episodes, as well as in lowering the amount of latent virus the animals harbored, according to the team’s report in the Journal of Virology.

However, dl5-29 was superior to the gD2 vaccine in producing the level of antibodies needed to neutralize the herpes virus.

“Based upon dl15-29’s biological and immunological properties,” Straus comments in a statement, “it appears to be the most compelling new vaccine candidate for genital herpes.”

SOURCE: Journal of Virology, January 2005.