Peter Palese and Taia Wang have written a compelling article that uses scientific facts to address the controversy over publication of research involving transmission of avian influenza H5N1 in ferrets. In response to calls in the media to destroy the viruses, curtail the research, and protect the public from frightening research, they write that “fear needs to be put to rest with solid science and not speculation”.
The authors begin with the facts: they indicate that the object of ferret-to-ferret passage of avian H5N1 influenza virus was to determine whether sustainable aerosol transmission could be achieved in this animal model. The finding that transmission in ferrets is conferred by a small number of mutations emphasizes the need for continued surveillance of H5 viruses and development of vaccines and antivirals.
Are these studies relevant to humans?
Ferrets are quite susceptible to infection with influenza viruses. However, it is not clear that all virus strains that replicate in and transmit between ferrets necessarily do so in humans. Ferrets are also more likely than humans to have disseminated, multiorgan influenza disease including neurological sequelae….one cannot directly extrapolate from the data to make predictions about humans.
Under the heading ‘fear’, they address the heart of this controversy, the notion that the fatality rate for human H5 infections is greater than 50%:
…in order for a case to be confirmed by WHO, a person must have an acute, febrile respiratory illness with known H5 exposure in the 7 days preceding and have molecular confirmation of H5 infection by a WHO approved laboratory. This definition does not allow for asymptomatic infections and essentially requires that a person actively seek medical help at a hospital that is equipped to draw samples and ship them to an approved laboratory….it seems unlikely that even a small fraction of the total number of infected cases has been accounted for under the WHO surveillance system.
They also review seroevidence in humans for H5 infections:
Of the 10 largest studies of which we are aware…eight report rates ranging from 0.2% to 5.6%….even if only a low percentage of the rural population is asymptomatically/subclinically infected, the case fatality rate that is offered by the WHO – and that is driving this controversy – is likely orders of magnitude too high.
The authors believe that selection of these papers for redaction by the National Science Advisory Board for Biosecurity appears arbitrary, considering what has been published on influenza in the past:
In 2005, the complete sequences for the 1918 pandemic influenza virus were published…in 2006, both Science and Nature published reports of specific mutations that enable the H5 viral hemagglutinin to bind human, rather than avian tissues. In 2012, a report from the CDC that bears striking resemblance, in principle, to the works by Fouchier and Kawaoka was already published in Virology: it describes mutations in an H5N1 virus that confer airborne transmissibility between ferrets.
Finally the address the question: Could the data from these two papers realistically be used to generate an H5N1 biologic weapon?
The answer is simply no.
Everyone should read this article, including anyone who is concerned about the safety of the H5N1 experiments; biosecurity analysts who do not seem to understand the underlying science; and science writers who propagate misinformation about the virus.
Hosts: 
The third annual installment of my virology course at Columbia University, Biology W3310, has begun. This course, which I taught for the first time in 2009, is intended for advanced undergraduates and will be taught at the Morningside Campus.
After we discussed newly discovered entry factors for ebolavirus and hepatitis C virus on
The finding of viral nucleic acid sequences in
Hosts: 
Renowned influenza virologist Peter Palese has penned an 







Moratorium on influenza H5N1 transmission research
20 January 2012
In letters to Science and Nature, the authors of the controversial avian H5N1 influenza virus transmission experiments in ferrets, together with other influenza virologists, have agreed to a 60 day moratorium on transmission research:
They write that research will continue on assessing the “transmissibility of H5N1 influenza viruses that emerge in nature and pose a continuing threat to human health”.
This research is being halted because of the concerns that ferret-transmissible H5N1 viruses may escape from laboratories. They argue that the finding in two laboratories that viruses with a hemagglutinin (HA) protein from highly pathogenic avian H5N1 influenza viruses can become transmissible in ferrets advances our understanding of influenza transmission. Nevertheless,
I agree in principle with this decision, because the argument over this research has become increasingly polarized in recent weeks, with a distressing demarcation between those who believe the work should proceed, and those who feel it should not be done. A dialogue to identify the crucial issues and develop plans to address them, while continuing this important line of research, is certainly welcome.
I am curious to see who will participate in the proposed dialogue. I do hope it will be a balanced forum: a fair mix of microbiologists, especially those working on influenza virus, and those interested in biosecurity. As I have said before, scientists will listen to the policy analysts, but the latter must also understand the science.
Update: Alan Dove has written an honest analysis of the moratorium announcement.
Related:
Palese: Don’t censor live-saving science
N.Y. Times: H5N1 ferret research should not have been done
Should we fear avian H5N1 influenza?
A bad day for science
Ferreting out influenza H5N1
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