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On New Bird Flu, From A Doctor Who's Been There: We Need Time

A worker at Sanofi Pasteur, the world’s larges influenza vaccine manufacturer. Some researchers in the United States have published letters in the journals Nature and Science arguing to create a more virulent strain of the H7N9 avian flu to prepare for its possible spread in humans. (Sanofi Pasteur/Flickr)
A worker at Sanofi Pasteur, the world’s larges influenza vaccine manufacturer. Some researchers in the United States have published letters in the journals Nature and Science arguing to create a more virulent strain of the H7N9 avian flu to prepare for its possible spread in humans. (Sanofi Pasteur/Flickr)

We wrote earlier this week about the latest avian flu news, concerning a new strain called H7N9 that has killed at least 43 people in Asia. Summary: A probable case of human-to-human transmission has been reported in China, and some flu researchers say they're going to alter the H7N9 virus in the lab in ways that will make it more dangerous, in order to understand and defend against it better.

I was left a little confused about those highly controversial plans to modify the virus. Very scary. What if it got out? On the other hand, bird flu is scary too. Shouldn't we do all we can to fight it?

I spoke with Dr. Michael V. Callahan, a Massachusetts General Hospital infectious disease and disaster medicine physician who deploys to large-scale disease outbreaks. He's the director of a Department of Defense-funded project to predict and defend against dangerous virus mutations. He is also an expert on flu outbreaks and one of the few Americans to have treated H7N9 patients last March in China.

How, I asked, does he see the letters in Science and Nature announcing the researchers' plans to modify the H7N9 virus?

Dr. Michael V. Callahan at Mass. General Hospital (Photo: Joseph Ferraro, MGH)
Dr. Michael V. Callahan at Mass. General Hospital (Photo: Joseph Ferraro, MGH)

"In the right environment, with peer review, these gains of function studies are revealing and will help us home in on those conserved, critical elements of influenza that we might someday be able to use to block [all strains of flu] with one vaccine," he said.

So how about the suggestion in the letter that the research should begin quickly in hopes of producing something of value by this winter?

"Both unwise and impossible," he answered. "DARPA [The Defense Advanced Research Projects Agency] has developed the world's fastest pathogen-to-vaccine capability, capable of 100 million doses in three months. This is the only process that could deliver vaccine by November, the start of flu season."

"Unfortunately, the vaccine capability is not fully approved by the FDA. The traditional cell and egg based vaccine systems require months to develop a 'production strain,' a hybrid of H7N9 and a 'tame' strain, which can be placed in cells and eggs.

“The entire process — from isolation, cross-breeding a production strain, testing, manufacturing and distribution — takes a minimum of seven months for influenza, the only pathogen for which we have well-tested systems. For another deadly virus, for which there is no precedent, the task could take from seven years to eternity. Witness, for example, the absence of an approved vaccine for HIV, which infects over 50 million people around the globe.”

'The stakes are high and the research is necessary, but a full scientific, security and ethical review must be completed.'

"In sum, the assertion that responsible research can be convened, a target can be identified, a vaccine production strain can be designed and a manufacturing campaign can be initiated is inaccurate. Those of us in industry, global public health and the federal government who have prior experience with emergency vaccine design and manufacture would not support that position using the current FDA-approved technologies."

Dr. Callahan, along with many others, explored the ethics of such questions in connection with recent concerns over another flu strain, H5N1, he said. "Our position is that the stakes are high and the research is necessary, but a full scientific, security and ethical review must be completed prior to this work being initiated."

"The Western nations must recognize the research competencies and burden of disease impacting other nations and include these partners in the dialogue. All nations agree that the severity of flu and the incidence of flu are increasing with global travel and co-location of sensitive reservoir species and vulnerable human populations."

"With flu, there are wildfires and there are brush fires. H7N9 is a brush fire, which if not successfully contained by an aggressive Chinese public health response, could have become a wildfire, posing a significant, even global, health threat. We need to learn from it, map it, control it, without making the problem worse by selecting a more human-fit strain that could become a wildfire that burns China and hits the global economy as H1N1 did."

"So we need time to convene a ethical, technical and security review, to ensure representation of nations at greatest risk and to convene the right team to do the gain-of-function studies in the appropriate secure environment, to make sure we work with a strain that is unfit for humans. That means that it has a built-in defect in another area that prevents survival outside of the lab, but still allows gain of function studies to be completed."

"Just to get silly, let's say it needs Coca Cola to survive, so you could be sure it didn't spread by depriving it of Coca Cola."

Readers, responses?

This program aired on August 9, 2013. The audio for this program is not available.

Carey Goldberg Twitter Editor, CommonHealth
Carey Goldberg is the editor of WBUR's CommonHealth blog.

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