This plain-looking silicone ring is more useful than it looks. Doped with an experimental antiretroviral drug, when worn in the vagina by women in sub-Saharan Africa it was shown to reduce the risk of HIV infection by as much as 61 per cent. The ring is part of a large study called ASPIRE, which is designed to determine whether an experimental antiretroviral drug called dapivirine can help prevent HIV infection. The study enrolled 2600 uninfected women between 18 to 45 years of age in sites around Malawi, South Africa, Uganda and Zimbabwe. All of the women were considered at high-risk for HIV infection.
Each woman was given either a dapivirine or placebo ring at random, which was replaced every four weeks. Over the duration of the study, which started in 2012, their health was monitored by the researchers.
The findings, published in the New England Journal of Medicine, found that the dapivirine ring reduced the risk of acquiring HIV by 27 per cent. When the team discarded data relating to women who didn't return during the study, that figure rose to 37 per cent.
Interestingly, when the team looked at data for just those women aged 25 and above, the figure shot up even further, to 61 per cent. The team notes that women under 25 seemed to use the ring less consistently, which could account for its decreased efficacy amongst the younger participants.
The ring is by no means a complete solution to HIV transmission. But it does provide an extra line of defence and is empowering for women in regions where use of condoms is often inconsistent. The researchers will continue to study the ring and its efficacy, particularly trying to establish how they can increase its effectiveness among younger women.
Image by International Partnership for Microbicides