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Déja-Vu On Avian Flu: Probable Human-Human Spread, Research Debate

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)

This is not my favorite topic, potential bird flu pandemics that could sweep humanity and kill hundreds of millions. But I also worry that a "cry wolf" phenomenon will set in, and then we won't be prepared when the Big One hits. So let's just consider, for a moment, the latest anxiety-producing avian flu news, about a strain called H7N9 that has killed at least 43 people in China.

Today brings two news items on this new strain: The BMJ medical journal reports the first case of probable human-to-human spread of H7N9, from a Chinese father who caught it from poultry to his daughter. And avian flu researchers publish a public letter in the prestigious journals Nature and Science saying they must produce "super-strains" of H7N9 — more easily transmitted, more resistant to attack — in order to understand the virus better and prepare to defend against it. (Science reports on some initial responses to the letter: Critics skeptical as flu scientists argue for controversial H7N9 studies.)

Science also offers this helpful round-up of the background, the reason why this all feels like flu déja vu. It's that this is familiar ground from the last avian flu scare, with the virus H5N1:

At issue are gain-of-function studies, in which researchers use several techniques to give viruses characteristics that they don't have in nature, such as the ability to infect new species or transmit more easily through the air. Such studies are critical to understanding the sometimes subtle changes that can make a bird virus a pandemic threat, some scientists argue, and to developing better vaccines and surveillance. But others are skeptical and say that just because scientists can do the experiments doesn't mean they should.
The dispute went public in late 2011, after Fouchier and virologist Yoshihiro Kawaoka of the University of Wisconsin, Madison, submitted papers on their mammal-transmissible H5N1 viruses to Science andNature, respectively. A U.S. government panel, the National Science Advisory Board for Biosecurity (NSABB), recommended against publishing complete versions, for fear the details might provide a bioweapon blueprint. Ultimately, a divided NSABB supported full publication, but only after H5N1 researchers had declared a voluntary moratorium on gain-of-function studies and the U.S. government imposed new regulations.

I spoke with Here & Now co-host Jeremy Hobson today about the latest bird-flu news, and here's a snippet (the full segment is on the Here & Now page here:

Jeremy asked whether there was really much of a threat from lab-made superviruses; aren't they carefully contained? My response:

It depends who you talk to. I spoke with Professor Marc Lipsitch, an expert on the epidemiology of flu at the Harvard School of Public Health, and he says the trouble is that if the experiments work, they could produce a virus that has an almost unprecedented combination of being able to spread and being able to kill people.

“Viruses get released from very high containment labs," he said. "It doesn’t happen much and we’re pretty good at containing things, but pretty good is not good enough if the threat is of a strain that can transmit and really infect a large fraction of the global population.”

So, Jeremy asked, how scared should we be?

Personally, I can always be scared, I said, but let's end on a reassuring note: Prof. Lipsitch says that first of all, it’s not for sure that this case in China really was human-to-human instead of  bird-to-human. And even if it is human-to-human, he says, that’s not unprecedented — the really scary thing that’s not happening at this point is an avian flu virus that’s easily transmitted from human to human. There’s been no sign of that with H7N9 at this point.

Readers, any particular H7N9 questions? Please post below...

This program aired on August 7, 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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