An intravaginal ring infused with the HIV antiretroviral tenofovir protected six out of six macaque monkeys from repeated exposures to simian HIV (SHIV), the National AIDS Treatment Advocacy Project (NATAP) reports. Presenting their findings at the 20th Conference on Retroviruses and Opportunistic Infections (CROI) in Atlanta, researchers from the Centers for Disease Control and Prevention (CDC) and other institutions manufactured a ring infused with tenofovir that administered an average of 2.3 milligrams of the drug each day. They then inserted the ring into the vaginas of six monkeys, replacing it every 28 days.

The investigators vaginally exposed the six monkeys as well as 12 control primates to SHIV once a week for up to 16 weeks. Eleven of the control monkeys became infected with the virus after a median four exposures. None of the monkeys with the intravaginal rings were infected. The rings proved well tolerated across five months of study.  

The researchers have imminent plans to begin a Phase I trial of the ring in humans.

To read the NATAP report, click here.

To read the conference abstract, click here.