Sharp Debate Over HIV Vaccine Failure

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," Mamoud 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.

By Todd Zwillich
Reviewed by Louise Chang
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