Strains of genital herpes in Africa are far more virulent than those in the United States, researchers at Harvard Medical School in the US report, a striking insight into a common disease with important implications for preventing HIV transmission in a region staggered by the HIV/Aids epidemic.
The researchers arrived at this finding by testing mouse model strains of the disease against vaccine candidates. All vaccines were far more efficacious in abating the US strain.
The challenge lies in formulating either a single vaccine that protects against both types of strains of the genital herpes virus or two different vaccines. The vaccine farthest along in development - headed for clinical trials in a year - works best against the US isolates of herpes simplex 2, but it also protects laboratory animals from the African viral strains if given in five-fold-higher doses.