The next generation of HIV prevention for women may be on the way: an intravaginal ring that delivers the antiretroviral drug tenofovir, or other drugs, for up to 90 days.
While the ring may not totally replace condoms, it does offer women and couples more choices for disease prevention, and could be a sweet alternative to begging a partner to wear a condom.
"We're just trying to give women more options to protect themselves," Patrick Kiser, associate professor of bioengineering at the University of Utah, told TakePart. Kiser is leading the development of one of the new rings, and one of the project's main missions is to reduce the rate of HIV infection globally, not just in the U.S.
Kiser presented findings on the new device this week at the American Association of Pharmaceutical Scientists annual meeting in Chicago. Collaborating on the project is CONRAD, a Virginia-based reproductive health research organization.
The ring is similar to existing contraceptive vaginal rings, which provide long-lasting birth control, and to rings that deliver estrogen replacement therapy to post-menopausal women.
The ring itself is made up in part of plastic tubing that absorbs water when it's in the body, necessary for delivering water-soluble drugs such as tenofovir, Kiser says. Tenofovir is one of the medications found in the combination medicine Truvada, recently approved by the Food and Drug Administration for HIV prevention.
So far Kiser's ring has only been tested in sheep, but intravaginal rings for HIV prevention are also being studied by others, including the National Institutes of Health and the Population Council.
The NIH's new study, ASPIRE (A Study to Prevent Infection with a Ring for Extended Use), was launched earlier this year. Researchers hope to enroll nearly 3,500 women in five countries to test the device.
NIH researchers will compare a silicone ring with the drug dapivirine, another antiretroviral medicine, to a ring with placebo and test how well the dapivirine works to reduce HIV transmission.
Kiser expects that human studies of the new ring he's helping to develop will begin in less than a year, but right now it's not known for sure how effective the new rings will prove in humans. Studies by the Population Council done in animals found a similar ring was more than 80 percent effective in preventing virus transmission.
Costs for the devices have not yet been estimated, although Kiser says the rings are inexpensive to make. "We expect it to be highly affordable," he says, adding that the rings can be washed and reused and can't be detected by a male partner.
The rings may be especially helpful to couples in which one is HIV-positive, to help avoid infection of the still-healthy partner, he says. "In principle it would reduce the need for condom use in some people. We would still promote condom use if folks don't know their HIV status."
At the end of 2009, more than one million people age 13 and older in the U.S. were living with HIV infection, according to the CDC. Globally, about 34 million children and adults are infected, according to the World Health Organization.
While much emphasis has been placed on developing drugs to cure HIV, prevention has been a focus of research as well, especially in countries where HIV rates are high.
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