Daily treatment with antivirals for HSV in women co-infected with both HSV and HIV can reduce the amount of HIV found in both blood and vaginal secretions, according to a new study published in the February 22 issue of the New England Journal of Medicine. The findings could have significant implications for HIV prevention.
An international group of researchers conducted a randomized, double-blind, placebo-controlled trial of HSV suppressive therapy with valacyclovir in Burkina Faso among 136 women infected with both HIV-1 and HSV-2. The results showed that having the herpes virus increased the replication of HIV, and also revealed that the quantity of HIV in the blood and vaginal secretions was reduced with daily treatment over 3 months.
As discussed in the last issue of The Helper, HSV and HIV act upon and enhance one another in various ways. For example, HSV-2 may influence the replication of HIV and accelerate the course of HIV disease. HSV-2 infection, in turn, has been shown to increase the risk of acquiring HIV.
Lead author Dr. Nicolas Nagot, of the London School of Hygiene & Tropical Medicine commented on the implications of the trial for future prevention efforts: “The results of the trial are striking. They show that valacyclovir significantly reduces the frequency and quantity of HIV detectable in genital secretions and, in addition, reduces the quantity of HIV in the plasma. As expected, there was also dramatic reduction in the detection of symptomatic and asymptomatic presence of HSV-2. The effects appeared to gradually increase over the 3 month follow-up period, with no sign of abating.”
While the findings will need to be confirmed by further research, they indicate a new way to possibly reduce the sexual transmission of HIV from already infected individuals to their partners. Dr Philippe Mayaud, one of Dr Nagot’s colleagues, noted, “Our results have important potential implications for public health and clinical practice, as HSV-2 control could become a new form of HIV prevention targeting HIV-infected individuals, as well as providing clinical benefits.”
Dr. Nagot also suggests that the results reinforce the need to focus on herpes vaccine development. “Importantly, an HSV vaccine that would either prevent HSV infection or diminish the clinical and subclinical manifestations of HSV with a similar efficacy on HIV as HSV suppressive therapy, would represent a long-lasting form of HIV prevention. The development and evaluation of an HSV vaccine should rank high on the international research agenda.”