Vaginal ring helps protect women against HIV infection: Two large studies

Kakaire A Kirunda, CNS Correspondent, Uganda
Two large clinical trials - The Ring Study and ASPIRE - conducted in four African countries have shown that a monthly vaginal ring containing the antiretroviral drug (ARV) dapivirine can safely help prevent HIV infection in women. In tele-media brief to select African journalists prior to last  night’s official release of the findings at the annual Conference on Retroviruses and Opportunistic Infections in Boston-Massachusetts, lead scientists said the dapivirine ring safely reduced HIV infection overall by 30 percent compared to those who used a placebo (dummy) ring among the 4588 volunteers who participated.

“What this means is that the dapivirine ring prevented about  one third of HIV infections – about 1 in 3 women who would have acquired HIV did not,” said Dr Jared Baeten, Microbicide Trials Network and University of Washington adding, “HIV risk was reduced by more than half (56 percent) among women older than 21 in the ASPIRE study. Effectiveness was 37 percent for women in the Ring Study.”

Dr Baeten further said that findings from the two studies strongly suggests consistent ring use is needed to achieve protection. But on a rather disappointing note, the scientists found little to no protection was seen in women ages 18-21 across both studies -15 percent in The Ring Study and no protection in ASPIRE.

None-the-less, this is the first time that two large scale studies have confirmed statistically significant efficacy (effectiveness) for a microbicide to prevent HIV. Scientists define statistical significance as the likelihood that a result or relationship is caused by something other than mere random chance.
However, it may be in late 2018 or early 2019 for the dapivirine ring to be available on the open market and used in combination with other prevention methods, according to Dr Annalene Nel, International Partnership for Microbicides, the developers of the ring.

She added: “We are now going to embark on the approval process from the World Health Organisation, the European Regulatory Agency and the respective national regulators. These processes take time. We will then be able to make the ring available.”

The Dapivirine ring is the first long-acting HIV prevention method designed for women, who bear the greatest burden of the HIV/AIDS epidemic. The ring uses a novel delivery method that slowly releases the ARV dapivirine over time, and is designed to remain in place for at least one month to provide sustained, discreet and easy-to-use protection against HIV.

Vaginal rings are already used in many countries to deliver hormonal contraception. The dapivirine ring uses the same technology by using an ARV instead of contraception as a way to offer women potentially long-acting protection against HIV.

The two independent clinical trials that started in 2012 were conducted at 22 sites in four African countries. ASPIRE by the U.S. National Institutes of Health with funding from the Microbicide Trials Network (MTN) enrolled 2629 women was conducted at 15 sites in Uganda, Malawi, South Africa, and Zimbabwe. Whilst the Ring Study which enrolled 1959 volunteers was conducted in Uganda and South Africa. All women in both studies received regular HIV testing and counseling, treatment for sexually transmitted infections, and condoms.

Kakaire A Kirunda, Citizen News Service - CNS
23 February 2016

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