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BANGKOK—Only a vaccine can end the AIDS epidemic, but the effort to develop one so far has been disgraceful, Seth Berkley, president of the International AIDS Vaccine Initiative (IAVI), said here at the International AIDS Conference.
"We've had one candidate fully tested in humans," he told reporters at the meeting. "That is a global disgrace."
Berkley said the world needs to make vaccines part of the comprehensive agenda against AIDS. "We need an enhanced science effort, using an industrial model," he told The Scientist. Candidates need to be developed in parallel and not sequentially, and "we must solve the remaining scientific challenges that are holding us back."
The number of vaccine candidates in the pipeline is now about 30. The trouble is, all the candidates seem to be working on a single approach, T-cell immunity, said Wayne Koff, IAVI's senior vice president for research.
Crucially, scientists have known for over a decade that a live attenuated vaccine is "extremely effective" in monkeys, Koff said. But researchers don't know why it works, or even if the primary component of protection is cell-mediated, or antibody, or mucosal immunity.
A systematic approach to monkey studies of HIV vaccines is needed, Koff told The Scientist. "We want to really change the model and look at statistically significant numbers of animals to be able to tease out exactly what is protective."
IAVI is "poised to create a consortium" on live attenuated vaccines, Koff said, to bring together the best scientists working on the problem and core resources such as facilities for high-throughput assays. "Over the next couple of years, we'll have a lot more systematic data than the field has seen."
To see a tenfold reduction in viral load with statistical significance, 15 monkeys would be needed in each arm of an experiment, said Koff, "but this has never been done before." It was done in the old days of polio vaccine, "when they used thousands of monkeys. We want to shift the paradigm to more of a Big Science approach to answer specific questions."
However, there is no intention of creating a live attenuated human vaccine, Koff said. "We want to use this research to find out what the mechanisms of protection of the live attenuated monkey vaccine are, and how to mimic its properties."
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