Acyclovir Strikes Out for HIV Prevention

In observational studies, herpes simplex virus type 2 (HSV-2) infection is associated with increased risk for HIV acquisition. Such an association is biologically plausible because HSV-2 infection disrupts the normally protective genital epithelium, and the resulting inflammation may recruit CD4 and other target cells for HIV to the genital tract. Could suppression of HSV-2 infection with acyclovir (ACV) reduce the risk for HIV acquisition?

To find out, investigators randomized 3172 HIV-negative, HSV-2–seropositive adults — 1358 women and 1814 men who have sex with men — to receive ACV 400 mg twice daily or placebo and examined the rate of new HIV infections in the two groups. The women were in sub-Saharan Africa; the men were in the U.S. an…