An experimental vaginal gel containing a drug used to treat the AIDS virus could prevent half of cases of genital herpes, according to a study done in South Africa.
Among women who used tenofovir gel, the annual rate of infection with the genital herpes virus, known as herpes simplex virus type 2 (HSV-2), was 10.2% versus a rate of 21% for women who used a placebo gel (based on 422 women who enrolled in the herpes study).
If the gel were to be approved and manufactured, and, ‘if a woman was concerned about acquiring HSV-2, this would be the best protection available,’ said Chief Author Dr. Salim Abdool Karim of the Centre for the AIDS Programme of Research in South Africa.
‘The problem is, right now it’s not available. And taking tenofovir tablets instead of the gel doesn’t have the same benefit,’ he said. ‘You see some protection with tablets, but the levels of protection are much lower.’
HSV-2 virus infects about one in five sexually active adults worldwide, or about 417 million people aged 15 to 49 years old, the study team writes in the New England Journal of Medicine. The virus is the most common cause of genital ulcers, and in South Africa, the estimated infection rate is 50 – 60%. Throughout sub-Saharan Africa the rate is thought to be as high as 80% in women and 50% in men.
The drug worked best among women who used the gel religiously. When drug levels in the vagina were high, the annual rate of HSV-2 was less than 6% compared to almost 16% when there was no detectable tenofovir in the vaginal fluid.