Researchers announced their disappointment upon finding that an anti-AIDS vaginal gel failed to stop HIV infection in their study of 6,000 South African women. The gel was the first of its kind to make it through late-stage testing.
Over 9,000 women volunteered for the study which was conducted from March 2004 through March 2007 in Gugulethu, Isipingo and Soshanguve. About 27 percent of the volunteers were found to already be infected with HIV and were disqualified from testing. The women were given either Carraguard, a microbicide developed by the nonprofit, New York-based Population Council, or a placebo gel without knowing which one they had received. They also received safe-sex counseling and condoms.
Among the participants, 4,244 completed the study overall. Almost 18 percent dropped out because they became pregnant, and the gel is not known to be safe for use during pregnancy. Also, 13 percent were unable to be located for follow up information.
Testing resulted in a rate of 3.3 infections per 100 women each year or 134 new HIV infections in the microbicide group and 3.7 or 151 in the placebo group.
“The results are comparable,” with no statistically significant difference, said Khatija Ahmed, a microbiologist who headed the study’s Setshaba Research Centre site near Pretoria.
Although researchers are still trying to determine the cause of the failure, they noted that women reported using the gel less than half the number of times they had sex, while only 10 percent said they used it every time as directed.
Researchers hope to improve upon the former gel with an updated formula which contains an experimental AIDS drug, MIV-150, that is already in the works. Development of a cream or gel women could use to lower their risk of getting HIV through sex has spanned the past two decades.
Research for a female-controlled method is crucial in poor countries where the women can’t always persuade their partners to use a condom.
Scientists discontinued two late-stage tests of a different gel last year because early test results showed that it might increase the risk of HIV infection rather than lowering it.
Researchers are still trying to determine if nonuse was an impacting factor in the latest study. Barbara Friedland, the study’s behavioral coordinator noted that if the rate of nonuse in the microbicide group was higher than in the placebo group “it could have had an impact on our final study results.”
Condom use reportedly increased from 33 percent at the start of the study to 64 percent during it.
The study was paid for by the Bill & Melinda Gates Foundation and the U.S. Agency for International Development, or USAID.
Jeff Spieler, an official at USAID, said that the testing showed some optimistic results for the future.
“We have always known that the path to developing a successful microbicide would be a long one.”
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Photo Caption: Carraguard is an odorless, tasteless, clear gel made from carrageenan, a derivative of seaweed. credit: Karen Tweedy-Holmes/Population Council
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