When an experiment finds out that a treatment doesn’t work as expected and that a cherished hypothesis just isn’t right, it’s not considered as newsworthy as an amazingly effective treatment that sparkles with potential. But the negative findings are just as important in their contributions to medical knowledge.
In that category, a new study dismisses the theory that treating herpes reduces patients’ risk of HIV infection, a strategy that was believed to hold promise. Researchers wrote in a commentary: It is time to reassess the hypothesis and to adjust prevention policy accordingly [The Lancet, subscription required].
Previous research had shown that people infected with genital herpes are more than twice as likely to become infected with HIV. Experts said there was a complex relationship between the two viruses that is still not entirely understood. When herpes ulcers erupt, that draws white blood cells to the skin to fight the virus. Unfortunately, those white blood cells also have receptors for HIV [AP]. Researchers hoped that by treating herpes patients with the antiviral medication aciclovir and preventing ulcer outbreaks, they could lower these patients’ risk of HIV infection.
The scientists studied 3,172 men and women in Africa, Peru and the U.S. who either received aciclovir or a placebo. The trial was in the last of the three stages of testing required for regulatory approval. The incidence of HIV infection was similar in the two groups after as long as 18 months, the study showed [Bloomberg].
In the report, which was published in The Lancet [subscription required], researchers say they don’t know why the treatment failed to reduce HIV infections, and said they might try another study with a more powerful drug or different dosage.