By Denise Grady and Donald G. McNeil, The New York Times, December 26, 2011
 |
| Ron Fouchier led a team that took one of the most dangerous flu viruses ever known and made it even more dangerous. Photo: Dirk-Jan Visser for The New York Times |
The young
scientist, normally calm and measured, seemed edgy when he stopped by his
boss’s office.
“You are not going
to believe this one,” he told Ron Fouchier, a virologist at the Erasmus Medical
Center in Rotterdam. “I think we have an airborne H5N1 virus.”
The news, delivered
one afternoon last July, was chilling. It meant that Dr. Fouchier’s research
group had taken one of the most dangerous flu viruses ever known and made it
even more dangerous — by tweaking it genetically to make it more contagious.
What shocked the
researchers was how easy it had been, Dr. Fouchier said. Just a few mutations
was all it took to make the virus go airborne.
The discovery has
led advisers to the United States government, which paid for the research, to
urge that the details be kept secret and not published in scientific journals to
prevent the work from being replicated by terrorists, hostile governments or
rogue scientists.
Journal editors are
taking the recommendation seriously, even though they normally resist any form
of censorship. Scientists, too, usually insist on their freedom to share
information, but fears of terrorism have led some to say this information is
too dangerous to share.
Some biosecurity
experts have even said that no scientist should have been allowed to create
such a deadly germ in the first place, and they warn that not just the
blueprints but the virus itself could somehow leak or be stolen from the
laboratory.
Dr. Fouchier is
cooperating with the request to withhold some data, but reluctantly. He thinks
other scientists need the information.
The naturally
occurring A(H5N1) virus is quite lethal without genetic tinkering. It already
causes an exceptionally high death rate in humans, more than 50 percent. But
the virus, a type of bird flu, does not often infect people, and when it does,
they almost never transmit it to one another.
If, however, that were
to change and bird flu were to develop the ability to spread from person to
person, scientists fear that it could cause the deadliest flu pandemic in
history.
The experiment in
Rotterdam transformed the virus into the supergerm of virologists’ nightmares,
enabling it to spread from one animal to another through the air. The work was
done in ferrets, which catch flu the same way people do and are considered the
best model for studying it.
“This research
should not have been done,” said Richard H. Ebright, a chemistry professor and
bioweapons expert at Rutgers University who has long opposed such research. He
warned that germs that could be used as bioweapons had already been
unintentionally released hundreds of times from labs in the United States and predicted
that the same thing would happen with the new virus.
“It will inevitably
escape, and within a decade,” he said, though he added that security measures
like restricting possession of the virus to fewer scientists and fewer
laboratories would lower the chances of that happening so soon.
But Dr. Fouchier
and many public health experts argue that the experiment had to be done.
If scientists can
make the virus more transmissible in the lab, then it can also happen in
nature, Dr. Fouchier said.
Knowing that the
risk is real should drive countries where the virus is circulating in birds to
take urgent steps to eradicate it, he said. And knowing which mutations lead to
transmissibility should help scientists all over the world who monitor bird flu
to recognize if and when a circulating strain starts to develop pandemic
potential.
“There are highly
respected virologists who thought until a few years ago that H5N1 could never
become airborne between mammals,” Dr. Fouchier said. “I wasn’t convinced. To
prove these guys wrong, we needed to make a virus that is transmissible.”
Other virologists
differ. Dr. W. Ian Lipkin of Columbia University questioned the need for the
research and rejected Dr. Fouchier’s contention that making a virus
transmissible in the laboratory proves that it can or will happen in nature.
But Richard J. Webby, a virologist at the St. Jude Children’s Research Hospital
in Memphis, said Dr. Fouchier’s research was useful, with the potential to
answer major questions about flu viruses, like what makes them transmissible
and how some that appear to infect only animals can suddenly invade humans as
well.
“I would certainly
love to be able to see that information,” Dr. Webby said, explaining that he
has a freezer full of bird flu viruses from all over the world. “If I detect a
virus in our activities that has some of these changes, it could change the direction
of what we do.”
Some scientists
dismiss fears of bioterrorism via influenza, because flu viruses would not make
practical weapons: they cannot be targeted, and they would also infect whoever
deployed them.
Dr. Fouchier said
it would be easier to weaponize other germs. Which ones? He would not answer.
“That should tell
you something,” he said. “I won’t tell you what I as a virologist would use,
but I would publish this work.”
However, some
experts argue that appeals to logic are useless.
“You can’t know who
might try to re-create H5N1,” said Michael T. Osterholm, director of the Center
for Infectious Disease Research and Policy at the University of Minnesota.
The A(H5N1) bird
flu was first recognized in Hong Kong in 1997, when chickens in poultry markets
began dying and 18 people fell ill, 6 of them fatally. Hoping to stamp out the
virus, the government in Hong Kong destroyed the country’s entire poultry
industry — killing more than a million birds — in just a few days. Buddhist
monks and nuns in Hong Kong prayed for the souls of the slaughtered chickens,
and world health officials praised Hong Kong for averting a potential pandemic.
But the virus
persisted in other parts of Asia, and reached Europe and Africa; that worries
scientists, because most bird flus emerge briefly and then vanish. Millions of
infected birds have died, and many millions more have been slaughtered. Since
1997, about 600 humans have been infected, and more than half died.
Dr. Donald A.
Henderson, a leader in the eradication of smallpox and now a biosecurity expert
at the University of Pittsburgh, noted that even the notorious flu pandemic of
1918 killed only 2 percent of patients.
“This is running at
50 percent or more,” Dr. Henderson said. “This would be the ultimate organism
as far as destruction of population is concerned.”
Dr. Fouchier was
working on AIDS when the first bird flu outbreak occurred. He immediately
became fascinated by the new disease and gave up AIDS to study it. He has
worked on bird flu for more than a decade.
The medical center
in Rotterdam built a special 1,000-square-foot virus lab for this work, a
locked-down place where people work in spacesuits in sealed chambers with
filtered air and multiple precautions to keep germs in and intruders out and to
protect the scientists from infection. Dr. Fouchier said that even more
security measures had been added recently because of the publicity about his
work.
The Dutch
government and the United States Centers for Disease Control and Prevention
approved the laboratory, and the National Institutes of Health gave the Erasmus
center a seven-year contract for flu research.
Because a
government advisory panel has recommended that the full recipe for mutating the
bird flu virus not be published, Dr. Fouchier declined to explain much about
how it was done.
But he previously
described the work at a public meeting, and various publications have reported
that the experiment involved creating mutations in the virus and then squirting
it into the respiratory tracts of ferrets. When the ferrets got sick, the
researchers would collect their nasal secretions and expose other ferrets to the
virus. After repetitions of this process, a strain of virus emerged from sick
ferrets last summer that could infect animals in nearby cages without being
squirted into them — just by traveling through the air.
The published
reports say five mutations were all it took to transform the virus. Dr.
Fouchier declined to confirm or deny that, and would say only that it took “a
handful” of mutations.
Looking back on
that day in July with Sander Herfst, the member of his team who told him the
virus had gone airborne, Dr. Fouchier said, “We both needed a beer to recover
from the shock.”
Then they planned
their next step, repeating the experiment to make sure the results were
reliable. There was one major obstacle: they had run out of ferrets. They
ordered a new shipment from Scandinavia. So they had to wait several weeks to
find out whether their discovery was real. Dr. Herfst took a vacation, timed to
end the day the ferrets arrived.
They ran the tests
again. Once more, A(H5N1) went airborne.
No comments:
Post a Comment