Semen seems to counteract microbicides that kill HIV

Guest post by Nathan Seppa

Antiviral microbicides effective against HIV in lab tests have had inconsistent results in people. A new study that includes semen and vaginal fluids, often missing elements in laboratory studies, finds that semen actually inhibits microbicides from killing HIV.

But the study, published in the November 12 Science Translational Medicine, also finds that semen didn’t diminish the antiviral effect of one microbicidal drug called maraviroc, which works differently from others. While most microbicides target components of HIV itself, maraviroc targets the receptor protein that serves as the entry point on cells that HIV is seeking to invade.

Maraviroc stopped infection when tested in cervical cells exposed to semen-treated HIV, suggesting that agents targeting these protein receptors on cells might be more promising than those aimed at the virus itself.