MEXICO CITY: Leaders in the quest for a vaccine against HIV
acknowledged on Monday that their mission was dogged by many problems
and cautioned that any breakthrough lay years in the future.
In a workshop at the International AIDS Conference, they said the AIDS pandemic would only be
defeated by a preventative vaccine, rather than treating people who are already infected.
But they admitted there have been many setbacks in crafting such a
shield, and some advocated a return to fundamentals, and said it is
time to draw lessons from failure. “Vaccine science is still more of an
art than a science,” said Tachi Yamada, executive director of the Bill
and Melinda Gates Foundation’s Global Health Programme, a major donor
to the vaccine effort.
Yamada pointed to fundamental gaps in knowledge about how the stealthy
human immunodeficiency virus (HIV) subverts the immune system.
Meanwhile, Yamada said funding, collaboration and cooperation urgently
had to be stepped up to avoid wasted or duplicated efforts. He said the
arena must be opened up to smart, revolutionary ideas, and a new
generation of vaccine researchers must be groomed. “We need big
investments for the future not only in the basic science of HIV
prevention, but also in clinical trials for an HIV vaccine,” Yamada
said.
“We have to be unafraid to fail. The road to success begins with
setbacks.” Alan Bernstein, director of the Global HIV Vaccine
Initiative, said the hunt was “at a critical crossroads” and any
success could only be viewed as “long term.” More than 25 million lives
have been claimed by AIDS and 33 million people are estimated to have
HIV. A safe, effective primer of the body’s defences – the frontline
antibody troops and the heavy artillery of the immune cells – remains
far out of reach, however.
Out of the 50 candidates that have been evaluated among humans, only
two vaccines have made it through all three phases of trials, and both
were rejected as quite ineffective. In the past year, one major vaccine
trial was halted after early results showed that it appeared to place
volunteers at greater risk of HIV infection. Another vaccine in
planning phases, involving tests among 8,500 subjects, was scrapped
after a similar formula, tested in 2007, was found to be largely
ineffective.
Researchers also urged governments and health communities to ramp up
male circumcision to prevent HIV infection, particularly in vulnerable
countries in eastern and southern Africa. Three studies were cut short
in 2006 after they showed strong evidence that male circumcision could
prevent HIV infection, but very little effort has been made to push for
more men to go under the knife, they said.
“This is a call to action… to call for male circumcision. It’s been two
years and still there is not enough money, focus to scale up effort and
more needs to be done,” said Dvora Joseph, head of the HIV department
at Population Services International, a US-based non-profit
organisation.
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