You’ve all seen the commercials, and may have friends that are using it – the contraceptive vaginal ring. It’s quickly gaining popularity in the U.S. and elsewhere, because it’s so effective AND convenient to use – just pop it in once a month and forget about it. The contraceptive vaginal ring has certainly sparked the interests of scientists working on HIV prevention, since use of a vaginal ring to deliver anti-HIV drugs would be a huge benefit in the fight against HIV, particularly for women.
Well, we’re one step closer to making that a reality: with funding from PEPFAR through USAID, researchers from the New York-based Population Council have found that a vaginal ring releasing an anti-HIV drug can prevent the transmission of SHIV in monkeys. Their findings were recently published in Science Translational Medicine. This study provides the first efficacy data on the delivery of an anti-HIV drug from a vaginal ring, and indicates strong potential for the success of such rings in women.
In their study, Council scientists examined whether vaginal rings containing a proprietary anti-HIV compound called MIV-150 could prevent the transmission of SHIV — a virus combining genes from HIV and SIV (the monkey version of HIV). Macaques received MIV-150 vaginal rings either two weeks or 24 hours before exposure to SHIV; a second group of macaques received placebo rings in the same manner. In both groups the rings were removed either immediately before or two weeks after exposure to SHIV.
It turns out that it didn’t matter whether the MIV-150 rings were inserted two weeks or 24 hours before virus exposure – only two of 17 macaques with the MIV-150 rings got infected (compared to the placebo group, in which 11 out of 16 became infected). What was interesting, though, was that the protection was lost if the MIV-150 rings were removed just prior to virus exposure: in that scenario, four of seven monkeys were infected.
This important study in monkeys provides additional scientific support for clinical trials that are already starting in southern Africa with another anti-HIV vaginal ring. This ring (releasing a drug called dapivirine) was developed by the International Partnership for Microbicides with support from USAID and a number of other donors. Further testing will take several years to complete.
What’s really exciting is that research organizations are working on vaginal rings that could deliver compounds that prevent HIV, other sexually-transmitted diseases such as HSV and HPV, and unintended pregnancy. This kind of combination prevention option especially for women, also known as “multipurpose prevention technologies,” is a new area of research spear-headed by USAID, in collaboration with other donors such as the National Institutes of Health (NIH), the U.K.’s Department for International Development (DFID), and the Bill & Melinda Gates Foundation that support research in family planning and reproductive health. Learn more about new contraceptive and multipurpose prevention technologies in our slideshow.