In 2009, researchers completed a study that showed a microbicide gel could protect women from HIV infection. The gel, known as CAPRISA 004, was nearly 40 percent effective in reducing the risk of infection during sex. The encouraging findings have led to follow-up studies. But just because a microbicide can block HIV, does not mean that women will use it.

Top ranking health officials called the CAPRISA 004 study historic. They said it showed that a microbicide could empower women to protect themselves from HIV/AIDS. It was something they could use without asking a man's permission. But would women use it outside of a clinical trial?

That's what a U.S.-funded study called Project LINK is trying to find out. Dr. Kathleen Morrow is leading a team of researchers at The Miriam Hospital in Providence, Rhode Island.

"It's actually the first study to my knowledge to link those physical, chemical and rheological properties and performance characteristics of a gel to the user experience - the actual sensory perceptions and experiences of the person using the product," she said.

Not all gels are alike

Morrow is a staff psychologist at The Miriam Hospital and associate professor of psychiatry and human behavior at the Warren Alpert medical school at Brown University. Morrow and her team are not studying whether the microbicide actually works. Instead, they want to know how women react to the gels themselves.

"If my clinical counterparts, who are actually developing the pharmaceutical sides of things – the drug side of things – the drug that they will actually put into the gel or ring or whatever they're going to put it into – if they do that and they do that well, and we have a product that will actually reduce HIV infections, the reality is it will only do that if people use it. So if people don't use it, it will sit on a shelf and will have no impact on the HIV pandemic," she said.

So they developed four different vaginal gels. None contained any antiretroviral drug, but each provided a different sensory experience when used. About 200 women tested the gels and told researchers what they liked or didn't like about them. They also said whether they would use a particular gel again.

Morrow said, "Microbicides in the context of sexual intercourse to prevent HIV disease requires human beings to behave in specific ways. Requires them to use the product. Requires them to use it consistently. Requires them to use it correctly. In my mind it's only going to happen if that experience of using the product is one that fits into their lives."

The opinions of the study participants are now being analyzed. The data will help determine the best formulation of microbicides that both blocks HIV and meets the needs and preferences of women.

The Project LINK study was funded by the National Institutes of Health as part of the Microbicide Innovation Program.