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Studies of deadly H5N1 bird flu mutations test scientific ethics

Dutch scientists have created a version of the deadly H5N1 bird flu that's easily transmitted. In an unprecedented move, a U.S. board asks that some details of the research not be published.

December 26, 2011|By Eryn Brown, Los Angeles Times
  • Workers remove dead chickens after they were killed in Hong Kong last week. Hong Kong slaughtered 17,000 chickens and suspended live poultry imports for 21 days after three birds tested positive for the deadly H5N1 bird flu.
Workers remove dead chickens after they were killed in Hong Kong last week.… (Aaron Tam, AFP/Getty Images )

In a top-security lab in the Netherlands, scientists guard specimens of a super-killer influenza that slays half of those it infects and spreads easily from victim to victim.

It is a beast long feared by influenza experts, but it didn't come from nature. The scientists made it themselves.

Their noxious creation could help prevent catastrophe in the battle against the deadly H5N1 bird flu that has ravaged duck and chicken flocks across Asia and elsewhere since the mid-1990s but has mostly left our species alone — for one crucial reason. Though H5N1 kills with brutality when it takes hold in a human, it infects extremely rarely and doesn't go on to easily spread between people.

Public health officials have long fretted that the virus may one day find a way to do so.

Now, in engineering what nature has so far not unleashed, the Dutch team and another in the U.S. that also has conducted sensitive H5N1 research have rekindled a debate that has smoldered since the 2001 anthrax attacks that killed five people.

The questions: Is some research too dangerous to publish? How do you make sure the wrong people don't get the information and the right people do?

In an unprecedented move, a government biosafety advisory panel has asked the Dutch and U.S. teams, as well as editors at two prestigious journals where their work has been accepted for publication, to omit crucial details about the research "that could enable replication of the experiments by those who would seek to do harm."

Experts said the events signaled a "new phase" for the U.S. National Science Advisory Board for Biosecurity, which was chartered in 2004 to help assess potential risks of biological research and has never before stepped in so aggressively.

"We'll have to see how it plays out," said Ronald Atlas, a biologist at the University of Louisville in Kentucky and former president of the American Society for Microbiology who has been involved in discussions about biosafety for more than a decade.

"How one decides who to share the information with — who do you trust, especially when you're not dealing with classified information and it's not just in the U.S. — is going to be hard to work out."

Ron Fouchier, the Dutch virologist whose lab created the new H5N1 that can readily spread between ferrets — animals that respond to influenza much as humans do — has no doubt that his research is worthwhile. Creating viruses like this one is the only way to study them and get out ahead of a pandemic, he said.

"It's all about predicting what will hit you next. We want to predict earthquakes and tsunamis; we also want to predict what will happen with the bird flu virus," he said. "This work needed to be done."

As far back as 1997, he wanted to figure out whether H5N1, which has killed nearly 60% of the roughly 600 people known to have contracted it, could evolve to spread efficiently from mammal to mammal. If it could, that might pose a catastrophic threat to humans.

"We would be in very deep trouble," he said.

The genetic path to such an outcome is unclear. Though scientists know that the key to stoking a flu pandemic comes from the virus gaining the ability to transmit through droplets from sneezes and coughs, they can't say just what changes in the virus bring that about.

And with H5N1, in any case, many scientists thought it was impossible. Strains carrying the H5 type of a key influenza protein that helps the virus bind to cells in a host had never evolved to travel through the air from person to person.

Even if H5N1 did evolve such an ability, some researchers reasoned that it might do so at the expense of its ability to take hold deep in the lung. And that would make it less lethal.

"They said it's never happened before, so it won't happen at all," Fouchier said. "To me, that was weak."

Over the course of a decade, Fouchier carefully began to test these assumptions about H5N1 by trying to create a version of the virus that could travel from ferret to ferret.

He got approvals from the necessary oversight groups. He secured funding from the U.S. National Institutes of Health. His workplace, the Erasmus Medical Center in Rotterdam, built a so-called Biosafety Level 3 Enhanced lab to house the experiments.

In such labs, all workers wear full-body suits and breathe through powered respirators, said Daniel Perez, a virologist at the University of Maryland in College Park who studies interspecies transmission of a different kind of bird flu, H9N2, in the same kind of facility. Air is purified coming in and out.

"There's no chance for the virus to escape," Perez said.

Fouchier and colleagues used a combination approach, engineering the virus and then stepping back to let nature take its course. They introduced key mutations into H5N1's genetic code and then infected the ferrets.

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