Washington — An audience eager for good news heard it July 25 at the XIX International AIDS Conference in Washington. Dr. Barton Haynes, a member of an elite circle of researchers on a quest for an AIDS vaccine, said he and his colleagues are more energized in their work than ever.
“The HIV vaccine field is invigorated. We are working hard. We are collaborating with one another, and we’re treating this problem as a global emergency,” Haynes said.
As a professor of medicine and immunology at the Duke University School of Medicine, Haynes has been on the hunt for an AIDS vaccine for 25 years.
The cause for new excitement in the field, he said, is discovery of a new type of antibody that will likely be more “potent” in battling HIV than any other ever seen.
“One of the things that has so energized the field is the discovery of a whole host of new broadly neutralizing antibodies that bind to vulnerable sites on the HIV envelope, the so-called envelope’s ‘Achilles’ heels,’” Haynes said.
He is also the director of the Center for HIV/AIDS Vaccine Immunology (CHAVI), funded by the U.S. National Institutes of Health. The consortium joins researchers from six universities and academic medical centers to focus the best of U.S. brainpower on overcoming the key immunological roadblocks that have bedeviled scientists so long.
One of those problems is HIV’s unusual capacity for mutation, for reinventing itself into another viral strain before the immune system is able to produce an antibody that can destroy it or inhibit its effectiveness and virulence.
For that reason, Haynes compares HIV to an arms race in its capacity to elude researchers, attack the human body and perpetuate itself in new and lethal forms.
“One country makes a bomb. Another country makes a bigger bomb. The first country makes an even bigger bomb; the second country retaliates with another bomb,” said Haynes. “Bigger and bigger, and so on and so on.”
HIV follows that pattern of mutation in 80–85 percent of people infected. But in another 10–15 percent, investigators have found a more robust response, which produces a more powerful antibody. Researchers are tracking some of these rare subjects, watching how their antibodies develop in hopes of also gaining insight into HIV’s mutations for survival.
Haynes said keeping vigil on the evolution of the virus in those patients could provide “a blueprint for vaccinologists” to understand the unusual capacity that some individuals have to produce effective antibodies against HIV.
Producing a vaccine to protect populations from HIV infection will require “completely new strategies of vaccine design that have not been used for vaccines to date,” Haynes said.
Vaccine development is proceeding on a second front also, working from the marginally successful trial of a vaccine tested in Thailand. That trial, reported in 2009, showed a slightly greater than 30 percent protection rate among vaccinated subjects. Research continues to provide a better analysis of how the vaccine produced the positive results among that group.
GLOBAL PROGRESS FOR WOMEN, CHILDREN
The theme of the XIX International AIDS Conference is “Turning the Tide Together,” selected by its primary sponsor, the International AIDS Society, and co-sponsors such as the Global Network of People Living with HIV and the International Community of Women with HIV/AIDS.
The U.S. global AIDS coordinator, Dr. Eric Goosby, is emphasizing the importance of making sure that women and children are riding that turning tide.
“The latest data are encouraging and a testament to the dedication and tireless work under way to virtually eliminate new pediatric infections,” said Goosby, who also leads the President’s Emergency Plan for AIDS Relief (PEPFAR). “The United States is committed to working with countries to succeed in this mission and achieve the goal of an AIDS-free generation.”
The data come from the Joint United Nations Programme on HIV/AIDS (UNAIDS), which released a global census on the AIDS epidemic just days before the conference began. New infections among children globally were down about 24 percent since 2009.
Providing antiretroviral therapy (ART) to pregnant, HIV-positive mothers has been a key initiative to bring on that change, with extension of such services almost doubling from 2009 to 2011.
Secretary of State Hillary Rodham Clinton is especially proud of the U.S. contribution to protecting mothers and their infants.
“In the first half of this fiscal year, we reached more than 370,000 women globally,” said Clinton when she addressed a session July 23. “We are on track to hit PEPFAR’s target of reaching an additional 1.5 million women by next year.”
Working with UNAIDS, PEPFAR is aiming to expand treatment for mothers who need it and to reduce mother-to-child transmission of HIV/AIDS to zero by 2015.