Vaginal ring shields some women from HIV in NIH-backed study

Woman holding the dapivirine vaginal ring tested in the NIH-funded ASPIRE study. -- Courtesy of the International Partnership for Microbicides

A large study funded by the National Institutes of Health (NIH) found that a drug-delivering vaginal ring could protect some women against HIV. The results come on the heels of more promising data, which show that the ring device can reduce women's risk of developing the infection.

The trial, which was conducted in four sub-Saharan African countries, showed that a ring releasing the antiretroviral drug dapivirine reduced women's chances of developing HIV by 27%. The ring worked the best in women older than 25, lowering their risk of getting HIV by 61%. Researchers published their findings in a recent issue of The New England Journal of Medicine.

"To help bring about an end to the HIV/AIDS epidemic, women--especially those in sub-Saharan Africa--need multiple options for HIV prevention," Jared Baeten, who co-led the study for the NIH-funded Microbicide Trials Network (MTN), said in a statement. "The ASPIRE study was an important step towards determining whether the dapivirine ring could become one such option."

Scientists kicked off the study in 2012 and have since enrolled more than 2,600 women ages 18 to 45 in Malawi, South Africa, Uganda and Zimbabwe. Women comprised more than half of the 25.8 million people living with HIV in sub-Saharan Africa in 2014, the NIH pointed out, so finding effective prevention tools for this population was critical.

Some women in the trial got a drug-delivering ring and others got a placebo ring. None of the women knew which ring they had received until the end of the trial.

Researchers found that while the ring reduced some women's risk of developing HIV, it did not significantly protect women younger than 25 from the virus. In particular, the ring did not prevent women ages 18 to 21 from contracting HIV. That could be because younger women did not use the ring as frequently.

"Women need a discreet, long-acting form of HIV prevention that they control and want to use," Anthony Fauci, director of the NIH's National Institute of Allergy and Infectious Diseases (NIAID), said in a statement. But "further research is needed to understand the age-related disparities in the observed level of protection," he added. NIAID plans to work with a panel of outside experts to chart next steps for the study.

The findings add to positive data in the field. A large, ongoing multinational clinical study, dubbed The Ring Study, recently found that the device helped prevent HIV in 31% of women. The ring worked especially well in women older than 21 years, researchers said.

- read the statement
- here's the NEJM study abstract

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