Less than 10 years ago, I remember hearing French virologist Francoise Barre-Sinoussi, PhD, winner of a Nobel Prize for co-discovering the virus, express deep pessimism about whether it would be possible to develop an AIDS vaccine, the holy grail of the epidemic.
But as Barton Haynes, MD, director of the Duke Human Vaccine Institute, said at the International AIDS Conference today, the field of vaccine research is enjoying a revival, with hopes renewed, thanks to a series of new developments in just the last few years.
“I can assure you the HIV vaccine field is invigorated. We are treating this problem as a global emergency,” said Haynes, who has been working in the field for 27 years and leads the NIH’s Center for HIV/AIDS Vaccine Immunology.
One of the challenges of vaccine development is that HIV is an extraordinarily diverse virus, changing its character every time it replicates. An infected person may harbor hundreds of thousands or millions of different variations of the virus. So a vaccine needs to generate an immune reaction that is clever enough to recognize all of these variants.
I can assure you the HIV vaccine field is invigorated.
Vaccine researchers were encouraged in their quest by the results of a trial among 16,000 people in Thailand, reported in 2010, which showed a 31 percent reduction in infections. The vaccine was all too limited in its effectiveness, but it nonetheless pointed the way forward.
Since then, researchers have been following some of the trial participants and identified some immune “correlates” – clues on what it is about the immune response that can help predict whether a vaccinated person will be protected or not, Haynes said.
At the same time, scientists have identified several potent new neutralizing antibodies with broad ability to recognize different viral strains, Haynes said. These can be combined with so-called adjuvants, which boost the immune response, to form the basis for new clinical trials.
Haynes likened the struggle for a vaccine to the global arms race: Every time a weapon is introduced, a new, more powerful one is built. In HIV, every time an antibody attacks a virus in the body, a new “escape” virus is created, and HIV wins.
Now, he said, “We hope to create the human HIV arms race with a vaccine and a strong adjuvant so the vaccinee wins.”
Ruthann Richter is a Scope contributor and writer in the medical school’s communication office. She is attending the International AIDS Conference in Washington, D.C. and is posting periodic updates on the happenings there. You can see all of her updates in our HIV/AIDS category.