The two studies presented Monday, February 22, demonstrated the effect of a vaginal ring as a way to deliver medication that can prevent HIV transmission.
The ring contains an antiretroviral medication called dapivirine, which prevents HIV from making copies of itself. In the ring, the drug is used as “pre-exposure prophylaxis,” or PrEP, slowly leaching out in the vagina and preventing the virus from taking hold in nearby cells.
In one of the studies, published online in the New England Journal of Medicine, more than 2,600 women in four countries — Malawi, SouthAfrica, Uganda, and Zimbabwe — over nearly two years, tested the dapivirine ring.
At the end of the study, the group of volunteers had 27% lower incidence of HIV than women given a placebo ring with no medication.
The studies also looked at age, and the researchers noticed that the ring did not seem to help women younger than 21. But among women over the age of 21 who used it, new HIV cases went down by 61%.
The second study carried out on 2,000 women in South Africa and Uganda, presented at the Conference on Retroviruses and Opportunistic Infections meeting in Boston, on Monday, shows similar result, with 37% fewer infections in women over 21 who were given the ring with medication.
Physicians also tested the women’s blood to see how much of the ring’s active ingredient was actually in the bloodstream. This way, they could tell if it had been removed and simply replaced for the checkup.
Why Age Differences
As the researchers said, these age differences are probably due in part to how the women used the drug. Much like the contraceptive NuvaRing, the dapivirine ring should be kept in every day and replaced once a month for maximum effectiveness.
The ring adds a new HIV prevention tool, which some experts say will be particularly useful in African countries where women are at highest risk for HIV infection. More than half of the 35 million people living with HIV worldwide are women, and the vast majority live in sub-Saharan Africa.
There is absolute reason to celebrate. But 27% is a lower number than any of us would like to see.
Mitchell Warren, executive director of AVAC, a global HIV-prevention advocacy group, told BuzzFeed News.
We obviously always want higher numbers. But 1 in 3 infections were prevented overall — and that’s huge.
Warren noted that other rings with anti-retrovirals are also being developed, as well as rings that could offer multipurpose protection, against not only HIV but pregnancy.
Like birth control, the more types of HIV prevention, the better, experts say.
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