A new trial of a vaginal ring containing an antiretroviral (ARV) drug that could prevent HIV transmission during intercourse is being initiated in South Africa. The nonprofit International Partnership for Microbicides (IPM) is conducting the trial.

Clinical trial IPM 015 will test the safety and acceptability of a flexible silicone ring that slowly releases the ARV drug dapivirine over 28 days. The ARV ring is being compared with a placebo during the trial, and 280 women in South Africa have volunteered to participate.

A vaginal ring releasing dapivirine has already proved to be safe in four European trials. If the current clinical trial in South Africa is successful, a Phase III trial will begin in 2011. The ring is manufactured by IPM.

Worldwide, more than 3,000 women contract HIV every day, and HIV/AIDS is the leading cause of death for women ages 15 to 49.