Update: The dapivirine ring has been found to reduce women's risk of contracting HIV by 56%, according to research presented this week at the AIDS 2016 conference in South Africa. Among women who used the ring most consistently (mostly older women), the risk was cut by 75%. Dr. Zeda Rosenberg of the International Partnership for Microbicides said in a statement that these findings suggest it "could be an important option for women who urgently need new tools to protect themselves from HIV."
This article was originally published on February 23, 2016.
The first HIV prevention tool designed specifically for women got a major vote of confidence this week, after the results of two major studies (one of which is ongoing) were announced yesterday. The technique in question: a vaginal ring containing antiretroviral drugs designed to stop the spread of HIV at the point of infection. Researchers behind these studies, known as ASPIRE and the Ring Study, were hopeful that this technology, which is already in use to deliver hormonal birth control, would be an easy, effective way for women in Africa to protect themselves from HIV.
The first HIV prevention tool designed specifically for women got a major vote of confidence this week, after the results of two major studies (one of which is ongoing) were announced yesterday. The technique in question: a vaginal ring containing antiretroviral drugs designed to stop the spread of HIV at the point of infection. Researchers behind these studies, known as ASPIRE and the Ring Study, were hopeful that this technology, which is already in use to deliver hormonal birth control, would be an easy, effective way for women in Africa to protect themselves from HIV.
The ring itself, the dapivirine ring, was developed by the International Partnership for Microbicides, a nonprofit aimed at preventing HIV through the use of microbicides, or substances that kill viruses on contact. Like the NuvaRing for contraception, the dapivirine ring works for a month at a time, as it slowly releases the antiretroviral drug dapivirine to block HIV from reproducing in healthy cells. A dual-acting ring, which prevents HIV and pregnancy, is also in development.
Both studies worked with female participants, most of whom were young, single, and were considered to be at high risk for HIV — high-risk behaviour includes having unprotected sex, sharing needles, and foregoing STI testing. These women were then given either a dapivirine ring or a placebo ring, and all received regular STI and HIV testing, along with free condoms and other advice for preventing HIV.
ASPIRE, the first of the two studies, recruited 2,600 women in Malawi, South Africa, Uganda, and Zimbabwe and found that, compared to the placebo group, 27% fewer women contracted HIV in the dapivirine group. Researchers noted that women who were 25 or older were more likely to be consistent with wearing their rings, which reduced the rate of infection even more dramatically within their age group.
Meanwhile, the Ring Study, which is still ongoing, has so far found that 31% fewer women developed HIV when using the dapivirine ring — among women older than 21, 37% fewer women contracted HIV. These early results, which are based on data from close to 2,000 women, aged 18 to 45 in South Africa and Uganda, were presented yesterday at the annual Conference on Retroviruses and Opportunistic Infections (CROI) in Boston.
In both studies, however, the researchers saw little to no added protection for women aged 18 to 21, and researchers are still working to figure out whether that has to do with usage or something physiological.
Still, researchers are optimistic that this represents a big step forward for women of all ages. "For the first time, we have two trials demonstrating that a female-controlled HIV prevention method can safely help reduce new HIV infections," said ASPIRE chair Jared Baten, MD, PhD, in a press release. He added that he's "optimistic about what these results might mean for women worldwide," and we have to agree.
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