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Science creeps onward in the fight against AIDS. Sometimes you learn useful information even when a test shows that a medication doesn't seem to do any good.
Here's NPR's Brenda Wilson with the story of Carraguard, developed to protect women from HIV.
BRENDA WILSON: Carraguard, a gel made from a derivative of seaweed is the first virus-killing microbicide to make it to the final phase of a large scale clinical study. Since 2004, more than 6,000 South African women participated in the study sponsored by the Population Council. Robin Maguire of the council says, as protection against HIV, Carraguard proved disappointing.
Ms. ROBIN MAGUIRE (Director of product development, Population Council): The study did not show the Carraguard was effective, even though there were less zero(ph) conversions(ph) in the Carraguard arm(ph) than the placebo, it was not statistically significant.
WILSON: In the Carraguard group 134 women converted to HIV positive, in the placebo group 151. But there was a great deal of variability in how often women used the gel. Only 10 percent used it consistently every time they had sex. Overall, it was used just 44 percent of the time during sex. That could've had an impact on the final results, but will take time to sort out. What researchers do know is that the gel is safe.
Ms. MAGUIRE: We've learned a lot from this study. We know that it's a safe and stable product, which could be used as a vehicle that would help to enhance the delivery of another antiretroviral or another anti-HIV agent.
WILSON: Over the years, other gels and foams were taken off the market because they increased the risk of HIV. Maguire says Population Council intends to move ahead with another study that combines Carraguard with an antiretroviral that is not currently used in HIV therapy. It is not absorbed into the bloodstream, but it appears to be effective against the virus in the laboratory.
Anna Forbes, the deputy director of the Global Campaign for Microbicides says that has been the challenge of finding a microbicide that works.
Ms. ANNA FORBES (Deputy director, Global Campaign for Microbicides): It's kind of like that old deodorant ad, you know. You need something strong enough to knock out HIV but gentle enough to be used everyday. The vaginal membrane is sensitive, obviously, and a product that gets inserted on a very regular basis has to not cause other kinds of vaginal infections which can facilitate HIV risk. At the same time, it has to have the ability to either block HIV from attaching to the cells or to disable the HIV in some other way.
WILSON: There's one other obstacle that researchers are going to have to overcome, finding a product, she says, that women will use consistently.
Ms. FORBES: Any of us who have experience using inserted birth control methods - a diaphragm, a cervical cap, a foam, a sponge, even putting on condoms - we know that one million and one things can get in between your intention to use the product and your actually using the product.
WILSON: But she says this study proves what many have doubted: that thousands of women in a developing country will hang in for the duration of a large-scale clinical study.
Brenda Wilson, NPR News.
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