The number of women infected with HIV has risen worldwide. In the hardest hit region, Sub-Saharan Africa, six out of ten adults living with the virus are women.
Researchers are gathering in Pittsburgh this week to discuss novel methods of preventing women from becoming infected. The products are called microbicides.
South Africa has more people living with HIV than any other country. Researchers say women who live in rural areas are especially vulnerable.
Dr. Samukeliso Dube is the African program director with the Global Campaign For Microbicides.
"The expectation is that they are a conduit for bearing children, and they are a conduit for sexual pleasure for men," Dr. Dube says. "And in these cultural setups, it's actually a taboo for them to ask their partners to wear a condom."
That can mean many partners in South Africa, where married men often have multiple sexual companions.
Dube says there's a need for protection that women can use discreetly.
"Being able to use a product without my partner's consent. I think that's the ideal for a woman who cannot negotiate for safe sex," Dube says. "Who dares not to talk about a condom. 'Cause I will just put my gel, knows one knows that I've got the gel, and I'm protected. So that's the ideal that we want."
The gel Dube is talking about is a microbicide. It's one in a line of products that contain drugs to kill HIV. People can insert them vaginally or rectally to prevent transmission.
At least that's the concept. But so far the reality has been disappointing.
Dr. Ian McGowan is co-principal investigator of the Microbicides Trial Network, a collaborative effort that conducts clinical studies worldwide.
He says five large scale trials of the first generation of microbicide gels showed they didn't work. One study even suggested an increased risk of HIV among women who used the product.
"What's exciting now is we're moving into the second generation products, which are really reformulations of anti-retroviral drugs," says McGowan. "The drugs we use in the clinic to treat patients with HIV, are being reformulated as gels, as rings, as other delivery systems."
McGowan says he has high hopes for these microbicides, because the drugs being used are more potent than the first generation.
Gels have been the preferred delivery method. But researchers are also experimenting with other ways to get the drugs inside the body.
Dr. Joseph Romano is the chief of product development for the International Partnership for Microbicides. He's working with something called a vaginal ring.
"Which is a sustained release device, that women can put in, leave for 30 days, and that'll deliver a drug over time, much like contraceptive rings that are currently available now," Dr. Romano says.
Romano is also testing vaginal films. These small, paper-thin strips work like Listerine breath fresheners.
"It's a very similar formulation, small, compact, doesn't require an applicator for insertion like a gel does. And these films can be put in vaginally by the women just using their finger. They rapidly dissolve, and spread throughout the vagina, and deploy the drug."
Vaginal tablets are another option.
While tablets, films, and rings are in their early stages of development, gels are further along in the process.
In fact, the first large scale trial testing the effectiveness of an anti-retroviral based gel has just been completed. Nearly 900 South African women were involved. The results will be announced in July.
Ian McGowan, with the Microbicides Trial Network, says researchers are putting together a tool box. The hope is the box will contain behavioral modification, diagnosis and treatment, a vaccine, and microbicides.
"Some people will use all of them, some of them, they'll be mixtures," McGowan says. "But at the end of the day, I'm very confident we're gonna reduce the incidence of HIV, you know? It's just a challenging, challenging journey."
And it's a journey that can't end too soon. Each day worldwide, an estimated 7,000 people become infected with HIV.