News around this week's AIDS 2010 international conference has been coming fast and furious, with results showing a gel capable of blocking HIV, the promise of antiretroviral drugs to prevent infection, and earlier, the discovery of two naturally occurring antibodies that could help push the development of a vaccine forward.

COURTESY OF UW

Dr. King Holmes, chair of University of Washington Department of Global Health and director of the UW Center for AIDS and STDs.

Researchers, foundations and nonprofits in Seattle are playing a key role in the global response. Using cost effective methods to prevent and treat HIV/AIDS has emerged as a central theme.

King Holmes, who is chairman of the Global Health Department at the University of Washington and an expert on HIV and other infectious diseases, said that prevention has not previously received the emphasis it deserves. Two of the most important advances in prevention are microbicide gel and male circumcision.

A new study showed that an antiretroviral gel significantly reduces a woman's risk of being infected with HIV and genital herpes, according to a report by the Centre for the AIDS Programme of Research in South Africa (CAPRISA).

Holmes called it "the first clear evidence of the effectiveness of a new intervention."

And he pointed out that the Microbicide Trials Network is headed by Sharon Hillier, a graduate of Washington State University and former UW professor. She is principal investigator and leads an international team of researchers and community and industry partners from seven countries and three continents.

As part of that network, another important trial known as the VOICE study is expected to start next month, looking at whether some of the medications used to treat HIV can also be used to prevent it. Jeanne Marrazzo, University of Washington associate professor of medicine, is the study's co-chair.

Finding solutions appropriate for women is especially important. In sub-Saharan Africa, where the epidemic has hit hardest, 60 percent of adults with HIV are women. While male condoms are effective, women can't always control if and when they're used, and women are twice as likely as male partners to acquire HIV during unprotected sex. Seattle-based PATH is home to the Global Campaign for Microbicides.

Marrazzo said researchers in the VOICE study will also try to determine whether women are more inclined to use a tablet or a gel.

For men, three recent studies showed male circumcision decreased the risk of acquiring the virus by about 60 percent. "That really is unequivocal," Holmes said. However some doctors remain opposed to the practice.

To make progress with limited resources, all of the known defenses against HIV must be applied, focused on all groups at risk and better coordinated around the world, Holmes said.

"Although scaling up antiretroviral therapy globally has lowered mortality rates," he said, "the number of new infections occurring every year exceeded the number of deaths. This is clearly a prevention failure. as long as the cumulative number of people with HIV infection continues to increase... we are going to have a bigger and bigger problem."

More than 35 million people are estimated to be living with HIV worldwide. In 2008 there were about 2.7 million new infections, and about 2 million AIDS related deaths, according to UNAIDS.

Looking longer term, basic research to identify new targets for vaccines has also gotten a boost recently.

I asked Alan Aderem, co-founder of the Institute for Systems Biology and a renowned immunologist working on the vaccine side, how he interpreted the latest discovery of antibodies effective against HIV.

I had profiled Aderem earlier this month, looking at the passion for social justice that motivates his science. Before his career in biology, Aderem spent most of his youth as an anti-apartheid activist in his native South Africa, where he is currently coordinating vaccine trials.

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Dr. Alan Aderem, co-founder of the Institute for Systems Biology.

Here's his response:

"The latest discovery defines an immunological Achilles heel of the virus. It uses structural studies to identify an important target for broadly neutralizing antibodies on the virus and demonstrates that an antigen can be designed that elicits the appropriate host response.

This is particularly important given that the recent Thai trial identified antibodies as crucial for the, albeit limited, protective response. Perhaps the most important aspect of the discovery is the methodology which allows for rational vaccine design; the method will clearly enable vaccine development against other pathogens.

I am not sure whether the finding signals a renaissance in the field but it will certainly energize it."