March 25, 2008 -- The recent failure of the most promising HIV vaccine ever developed has scientists taking stock and wondering where to go next.
After more than 20 years of research, answers to that question are scarce.
"We have to admit to ourselves that we don't know how to make an HIV vaccine right now," said Beatrice H. Hahn, MD, a microbiologist at the University of Alabama at Birmingham.
Hahn spoke in front of hundreds of researchers gathered in Bethesda, Md., to try to brainstorm ideas for finding a vaccine for HIV; the virus has killed 25 million people worldwide and now infects an estimated 33 million, according the World Health Organization.
The meeting comes several months after the drug company Merck announced it was halting human trials of its experimental HIV vaccine. Not only did the vaccine not work to prevent infection, but it also didn't reduce the amount of virus in people who became infected; there were also indications suggesting it may have made it easier for some people to contract the virus.
The failure has researchers and policy makers locked in a debate. Some are calling for more money for testing vaccines similar to the failed Merck vaccine already in the pipeline. Others want to abandon the vaccines under testing and start from scratch.
"Nothing currently around is going to cause significant protection, in the opinion of many of us," Hahn said. She counts herself among the leading scientists calling on the National Institutes of Health (NIH) to sharply reduce support for testing existing experimental vaccines. The money should be spent instead on basic scientific research aimed at finding new approaches to a vaccine, these scientists say.
Funding HIV Research
NIH officials say they've been hurt by five years of flat funding from Congress. One effect of the shortfall is dwindling support for young researchers who could come up with new ideas, they say.
"The easy things have been done," said James Hoxie, MD, who directs the Penn Center for AIDS Research at the University of Pennsylvania.
Wednesday's meeting was part scientific strategy session, part group therapy session for a field stunned by its lack of progress.
Several leading scientists, including Anthony Fauci, MD, head of the National Institute for Allergy and Infectious Diseases, have offered stark comments recently warning that an AIDS vaccine may never be found.
Hoxie implored the group to face head-on Merck's failure, and the failure of other HIV vaccines before it.
"It comes with the territory. It is part of the process, we have to be willing to accept it, we have to be willing to fund it," he said.
"It is only one step back," said Adel Mahmoud, MD, PhD, a Princeton University professor of microbiology and the meeting's co-chair. "The status quo and finger pointing isn't going to take us anywhere."
Fauci was more enthusiastic: "Everything is on the table to look at." He added that that he was "unambiguous" about the need to shift more funding toward basic scientific discoveries that could lead to new vaccines.
HIV Vaccines: What Comes Next?
But earlier this week several HIV research advocacy groups called for the U.S. government to abandon efforts to develop an HIV vaccine. Homayoon Khanlou, MD, U.S. chief of medicine for the AIDS Healthcare Foundation, said that the money should instead be spent on increased HIV testing and treatment, which both help cut the risk of HIV transmission.
All the clinical trials that have been done with the vaccine have yielded no results," Khanlou told reporters. "They've left us with no clue in terms of which way to go."
Few researchers seemed willing to consider abandoning vaccine efforts entirely. But several described their field as being a crossroads.
"The idea that we shut everything we have done and get to do something else is absolutely insane," Mahmoud said.
He showed the audience of scientists a slide quoting Winston Churchill's famous speech to a group of British students during World War II. "Never give in. Never give in. Never, never, never, never," it read.