HealthDay News—An investigational vaccine effectively prevents herpes simplex virus type 1 (HSV-1) but not HSV type 2 (HSV-2) genital disease and infection, according to a study published in the Jan. 5 issue of the New England Journal of Medicine.
Robert B. Belshe, MD, of Saint Louis University, and colleagues conducted a randomized, double-blind field trial involving 8,323 women aged 18–30 years who were seronegative for HSV-1 and HSV-2. The investigational HSV-2 vaccine consisted of 20 micrograms of glycoprotein D from HSV-2, with alum and 3-O-deacylated monophosphoryl lipid A as an adjuvant; the control vaccine was inactivated hepatitis A vaccine. Subjects received either the HSV-2 vaccine or the control vaccine at months zero, one, and six, and were followed for the development of genital herpes disease due to HSV-1 or HSV-2 from one month after the second dose through month 20.
The researchers found that, overall, the HSV vaccine was 58% effective against HSV-1 genital disease and 35% effective against HSV-1 infection (with or without disease). The vaccine was not efficacious against HSV-2 infection, even though it elicited the production of antibodies against HSV-2. These results were surprising given the previous efficacy demonstrated with this type of vaccine against HSV-2 and were attributed to the different patient population involved in this study. Localized injection site reactions, including redness, swelling, and pain, were reported more frequently in women receiving the HSV-2 vaccine than in those receiving the control vaccine.
“Although the development of a vaccine that provides protection against HSV-1 genital disease is a substantial step forward, additional progress is needed before a herpes vaccine is likely to be approved for general use. Any candidate vaccine will probably have to have proven efficacy against both HSV-1 and HSV-2 disease,” the authors write.
The study was funded in part by GlaxoSmithKline; several authors disclosed financial relationships with GlaxoSmithKline and/or other pharmaceutical companies.