Luminaries call for continued support for an AIDS vaccine to end the epidemic

Aug 10 2008

Discussions about how to manage AIDS in the long term and how to improve prevention efforts globally took center stage at this year's International AIDS Conference (IAC) held in Mexico City.

Unlike previous IAC conferences, this year's event did not have a plenary session focused on vaccines. But that did not stop luminaries and vaccine advocates alike from calling for continued support for an AIDS vaccine to end the epidemic.

"The end of AIDS is nowhere in sight," said Dr. Peter Piot, Executive Director of the Joint United Nations Programme on HIV/AIDS in remarks made during the opening ceremony of the conference.

"It's true that the number of infections is declining, but consider this: if the world can be satisfied with 2.7 million people infected per year, 7,500 per day, then I'm not sure where the standards are for declaring something a total disaster…What I see is that we are making progress through combination prevention, but in order to stop the epidemic, there's no doubt that we'll need a vaccine," Piot later said at a press conference hosted by the International AIDS Vaccine Initiative (IAVI) announcing the release of the organization's AIDS Vaccine Blueprint 2008.

"There is no greater tool to end AIDS than a preventive vaccine," said Craig McClure, Executive Director of the IAS, in a satellite session Wednesday evening.

At the start of the conference, the U.S. Centers for Disease Control and Prevention released new AIDS epidemic figures, based on a revised methodology, indicating that the number of infections in the U.S. were 40 percent higher than previously estimated. By both the old and new counting methods, the number of new infections remained roughly the same despite a 40 percent increase in U.S. prevention funding from 2005 to 2008. "Even in a country like the U.S., with significant resources and education dedicated to prevention, we're still losing the battle against AIDS, especially among certain high-risk populations," said Dr. Berkley, President and CEO of the International AIDS Vaccine Initiative.

"The bottom line is that we need a long-term solution to this epidemic. We need a vaccine if we are to turn the tide on AIDS," said Berkley.

The AIDS Vaccine Blueprint 2008, released by IAVI at the conference, sets forth the organization's recommendations for the future of AIDS vaccine research and development.

"It's clear 25 years after the discovery of the virus that we're on a long journey, and it's not going to be a straight line. That's why I think that the Blueprint 2008, released by IAVI, is such an important document. Long journeys require roadmaps and they require benchmarks of how we're doing-and both of those are in this year's Blueprint," said Dr. Alan Bernstein, Executive Director of the Global HIV Vaccine Enterprise.

Berkley highlighted that the main recommendation from the report is to "divide up the mission into a set of interim milestones. This is a way to measure progress, to hold people accountable."

"The second recommendation is a practical one: we have to trim and significantly improve the pipeline. We believe that the 30-odd candidates in the pipeline should be trimmed based on their probability of success. Resources from these candidates should be re-directed instead towards solving the biggest challenges facing researchers today," Berkley added.

Finally, Berkley stressed that "to move the AIDS vaccine field forward, we have to sustain the effort. We need a new cadre of young researchers. We need stable and predictable financing that is flexible."

Vaccine experts highlighted the significant progress made in AIDS vaccine science in recent years, including the knowledge gained from the STEP and Phambili trials in which an AIDS vaccine candidate developed by Merck failed to show efficacy. They stressed that these incremental advances will inform future vaccine design.

Dr. Tachi Yamada, President of the Global Health Program at the Bill & Melinda Gates Foundation, stated that "failure is a momentary setback on the road to success" during a presentation at a conference session on the future direction of vaccine and microbicide research.

Vaccine experts made a clear distinction between the failure of the vaccine candidate tested in the STEP and Phambili trials to show efficacy and the success of the trial itself to answer scientific questions, as all trials are designed to do.

At a satellite session on Wednesday evening, Dr. Peggy Johnston, Director, Vaccine & Prevention Research Program, Division of AIDS, NIAID, said that the analysis of the STEP results has taught the field, among other things, that smaller trials can produce results, that non-human primate models have to be rethought and that there is a possible impact on infection from prior exposure to vectors used to deliver antigens in vaccines.

Berkley, noted that "the field should not be discouraged by negative results." An AIDS vaccine is still urgently needed and evidence in humans and animal models has shown us that it is possible. "Developing a vaccine may take more time and innovation than we once imagined, but we are confident that science will prevail."

"Scientists and those who support their work - private corporations and governments alike - should redouble their commitments," Berkley added.

To that end, the Spanish government increased its commitment to AIDS vaccine development by announcing at the conference that it would be allocating three million Euro to IAVI. A new report tracking funding for biomedical HIV prevention research and development was also released in Mexico City and called for sustained funding for vaccine, microbicide and other HIV prevention research.

Experts acknowledged that an AIDS vaccine is a long-term endeavor, but one that can and will not be abandoned. History has shown that vaccines are the only tools that have ended major viral epidemics.

"The challenges are huge but I have no doubt that we will live in a world without HIV some day," Yamada said.

In a pre-conference meeting about funding for AIDS vaccine research and development, Dr. David Kihumuro Apuuli, Director General, Uganda AIDS Commission, said, "Nearly all of us in this room were born into a world without AIDS. We owe it to future generations to work to leave them a world without AIDS."

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