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PostPosted: Thu May 03, 2012 2:55 pm 
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Although the CDC and Fouchier papers used a PB2 with E627K, the Kawaoka paper used H1N1pdm09 for internal genes including PB2. H1N1pdm09 PB2 does not have E627K, but does have G590S and Q591R, which facilitates human transmission.

Recent sequences of H5N1 recombinants includes one isolate, A/chicken/Egypt/Q1182/2010, that has a PB2 gene that is largely a recombinant between seasonal H1N1 and H1N1pdm09. Consequently, it does not have E627K, but does have G590S and Q591R.

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PostPosted: Thu May 03, 2012 6:09 pm 
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Commentary invited by editors of Scientific American

Why Nature Published the Controversial Mutant Bird-Flu Paper

By Nature, Internaltional Weekly Journal of Science | May 3, 2012| 1

Nature Volume 485 Number 7396 pp5-142
The following is an editorial from Nature magazine, reposted here with permission. It was originally posted May 2 with the title, “Publishing risky research.”

This week sees the online publication of the paper ‘Experimental adaptation of an influenza H5 HA confers respiratory droplet transmission to a reassortant H5 HA/H1N1 virus in ferrets’ by the Japanese–US team headed by Yoshihiro Kawaoka at the University of Wisconsin-Madison (M. Imai et al. Nature 10.1038/nature10831 (2012). See also pages 7 and 13, and H.-L. Yen and J. S. M. Peiris Nature http://dx.doi.org/10.1038/nature11192; 2012). Kawaoka’s paper was one of two submitted last August, reporting mammalian transmissibility of avian flu as a result of artificial genetic manipulation, the principal scientific interest of which arises from the small number of mutations found to be necessary. The other paper, by a team headed by Ron Fouchier at the Erasmus Medical Centre in Rotterdam, the Netherlands, is expected to appear soon in Science.

As has been much discussed in Nature, both papers were independently assessed by the US National Science Advisory Board for Biosecurity (NSABB) while being considered by the journals. The NSABB’s recommendation, communicated to the journals in November last year, was not to publish the essential methods and data. Although such a recommendation has no statutory force, it makes any researcher or publisher pause. There followed months of public debate and two two-day meetings involving flu experts and other stakeholders, one held by the World Health Organization (WHO) and the other by the NSABB. After the second, at the end of March, the NSABB essentially reversed its position, and Nature made its own decision to proceed.

Lessons learned
As the economist John Maynard Keynes reportedly said: “When the facts change, I change my mind.” But the essential scientific elements in the Kawaoka paper were unchanged between the first and second NSABB deliberations. It is now clear that the committee’s original deliberations were too limited, especially given the enormous implications for flu research of a recommendation against publication. Yet as a body that aims to anticipate and scrutinize the security risks of biological research, the NSABB is unique worldwide, and it is desirable to have such a forum. The discussion that followed the board’s first decision would not have been as valuable or as prompt had it concerned hypothetical cases. Yet there are justified concerns among the research community about the NSABB’s processes, and these processes should be reviewed.

Some lessons have emerged that point to actions and policies for the future. First, it was worth deliberating at length on the possibility of redacting the key findings of the paper instead of simply rejecting it. (Rejection has long been an option if Nature is advised by security experts that the risks of publication exceed the benefits.) There was also the option that the full paper might be distributed by some third party, to selected recipients only. Having now considered these matters in depth, the editors of this journal have decided that we will not consider either alternative for papers in Nature in the foreseeable future. A paper that omits key results or methods disables subsequent research and peer review. Furthermore, after much internal and external deliberation, we cannot imagine any mechanism or criterion by which to sensibly judge who should or should not be allowed to see the work. Nor do we believe that any restricted information distributed to university laboratories would stay confidential for long.

We are aware that the lack of an option for restricted publication has its own risks in a discipline in which results might be both beneficial to the public benefit and a threat to security. We will willingly explore ways out of this dilemma.

One major risk amid these discussions is that younger researchers might be discouraged from entering a field that is subject to security constraints. But the attitudes of biosecurity experts are more encouraging than is widely appreciated.

As far as Nature is aware, formal assessments by security agencies have led to recommendations that the Kawaoka paper be published. This includes an independent assessment that we commissioned from a non-US biological-defence agency, whose advice can be found at go.nature.com/wglsea. In subsequent discussions with biosecurity researchers, there has been a striking unanimity: where there is a benefit to public health or science, publish! It has been enlightening to see how scientists in this secretive arena see the open scientific enterprise as their best recourse in times of potential trouble.

The third most important lesson is about biosafety. Here there are real concerns: humans lack immunity to flu viruses with an H5 haemagglutinin protein, and an accidental release of a mammalian-transmissible H5 virus would have the potential to cause a pandemic were it to transmit between humans. A key component of the second round of NSABB deliberations was a clear presentation by Kawaoka of his team’s very rigorous security processes and set-up, including physical arrangements, training and due diligence exercised with personnel.

Such a reassuring picture is not globally applicable. The standards of these labs (fully described in the Kawaoka paper) were widely quoted as biosafety level (BSL) 3 enhanced. The WHO discussion considered such standards essential, and worried that to require the distinctly more demanding BSL-4 standard would shut down the research. However, ‘BSL-3 enhanced’ is not a formally established standard. What is more, not every country may have sufficient regulatory systems and robust laboratory cultures of safety. This is a key issue as the self-imposed moratorium on work by flu-transmissibility researchers continues.

The WHO will soon release guidelines about international standards for biosafety. The signs are that these will highlight key issues and aspects of good governance, but will not themselves provide a framework for strengthened implementation. The absence of such a framework is an urgent concern for all researchers working with dangerous organisms, and for all who fund and publish their work.
http://blogs.scientificamerican.com/gue ... flu-paper/

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PostPosted: Sun May 06, 2012 11:15 am 
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niman wrote:
Experimental adaptation of an influenza H5 HA confers respiratory droplet transmission to a reassortant H5 HA/H1N1 virus in ferrets

One of the four mutations we identified in our transmissible virus, the N158D mutation, results in loss of a glycosylation site. Many H5N1 viruses isolated in the Middle East, Africa, Asia and Europe do not have this glycosylation site. Therefore, only three nucleotide changes are needed for the HA of these viruses to support efficient transmission in ferrets. In addition, the H5N1 viruses circulating in these geographic areas also possess a glutamic-acid-to-lysine mutation at position 627 in the PB2 protein, which promotes viral replication in certain mammals, including humans40, 45. Therefore, these viruses may be several steps closer to those capable of efficient transmission in humans and are of concern.

Correspondence to:
Yoshihiro Kawaoka

http://www.nature.com/nature/journal/va ... 10831.html

Only one public HA sequence, A/Egypt/3300-NAMRU3/2008, from human clade 2.2 cases (in Egypt, Turkey, Azerbaijan, Iraq, Djibouti, Nigeria, Bangladesh) has an N linked glycosylation site at position 158.

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PostPosted: Fri May 11, 2012 11:30 am 
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http://www.medpagetoday.com/upload/2012 ... e10831.pdf

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PostPosted: Sun May 13, 2012 11:28 am 
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Kawaoka paper published on aerosol transmission of H5 influenza virus in ferrets

2 May 2012


One of two papers on avian influenza H5N1 virus that caused such a furor in the past six months was published today in the journal Nature. I have read it, and I can assure you that the results do not enable the construction of a deadly biological weapon. Instead, they illuminate important requirements for the airborne transmission of influenza viruses among ferrets. Failure to publish this work would have compromised our understanding of influenza viral transmission.

The paper from Kawaoka’s group focuses on the viral hemagglutinin (HA) protein, an important determinant of whether influenza viruses can infect birds or mammals. In the image, the HA is shown as blue ‘spikes’ on the virion surface; a single HA molecule is shown at right. Avian influenza viruses prefer to attach to cells via a specific form of sialic acid that differs from the form bound by mammalian influenza viruses. This difference in receptor preference is one reason why avian influenza viruses do not transmit among mammals.

Kawaoka’s group used a random mutagenesis and selection approach to identify amino acid changes in the avian H5 HA protein that allow it to bind human receptors. These changes are located around the sialic acid binding pocket in the HA head (figure). Some of the amino acid changes were previously known, but there are also some new ones reported, expanding our understanding of how the HA binds sialic acids. Some of the HA amino acid changes allow virus binding to ciliated epithelial cells of the human respiratory tract (wild type H5 HA cannot). All of this is important new information.

The H5 HA genes with these amino acid changes were then substituted for the HA gene in a 2009 H1N1 pandemic virus, and this reassortant virus was inoculated intranasally into ferrets. The viruses did not replicate well in the ferret trachea, but viruses recovered from the animals contained a new change in the HA protein that improves replication. This change (asparagine to aspartic acid at amino acid 158) is known to prevent attachment of a sugar group to the HA and enhance binding to human receptors. Viruses with this change probably have a replicative advantage in ferrets.

A reassortant virus with HA amino acid changes N158D/N224K/Q226L transmitted through the air to 2 of 6 ferrets. Viruses recovered from one of the animals contained a new change in the HA protein, T318I. A virus with four amino acid changes in the H5 HA (N158D/N224K/Q226L/T318I) replicates well in ferrets and transmits efficiently, although the infection is not lethal.

Even more interesting are the results of experiments to understand how these HA amino acid changes affect viral transmission. The N224K/Q226L amino acid changes that shift the HA from avian to human receptor specificity reduce the stability of the HA protein. The N158D and T318I changes, which were selected in ferrets, restore stability of the HA.

There are three key questions concerning this work that must be answered.

Would an H5N1 virus with the changes N158D/N224K/Q226L/T318I transmit among humans? Probably not. The virus tested by the authors derived 7 of 8 RNA segments from a human H1N1 strain, which is well adapted for human transmission. It is likely that changes in other avian influenza viral proteins would be needed for human transmission. It might also be that entirely different changes in the H5 HA are required for transmission in humans compared with ferrets.

Is this information useful for the surveillance of circulating H5N1 strains; specifically, would the emergence of these HA changes signify a virus with pandemic potential? I don’t believe so. These are mutations that enhance the transmission of H5 viruses in ferrets, and their effect in humans is unknown. Ferret transmission experiments are not meant to be predictive of what might occur in humans.

If these results are not predictive of what might happen in humans, why were these experiments done? (to paraphrase Laurie Garret at the New York Academy of Sciences Meeting on Dual Use Research). A substantial portion of this work goes far beyond surveillance of H5N1 strains: it provides a mechanistic framework for understanding what regulates airborne transmission of avian H5 influenza viruses. In the Kawaoka study, amino acid changes that improve the stability of the HA protein were selected for during replication and transmission of the H5 viruses in ferrets. In other words, stability of the HA protein is an important property that allows efficient airborne transmission among ferrets. Additional experiments can now be designed to extend this idea. If such stabilizing changes can be shown to be important for transmission of human strains, then they might be a valuable marker of influenza transmission.

The Kawaoka paper is a significant piece of work that substantially advances our understanding of what viral properties control airborne transmission of influenza viruses. To view it as enabling construction of a bioweapon is highly speculative and fundamentally incorrect.

M. Imai, T. Watanabe, M. Hatta, S.C. Das, M. Ozawa, K. Shinya, G. Zhone, A. Hanson, H. Katsura, S. Watanabe, C. Li, E. Kawakami, S. Yamada, M. Kiso, Y. Suzuki, E.A. Maher, G. Neumann, Y. Kawaoka. 2012. Experimental adaptation of an influenza H5 HA confers respiratory droplet transmission to a reassortant H5 HA/H1N1 virus in ferrets. doi: 10.1038/nature10831.

http://www.virology.ws/2012/05/02/kawao ... in-ferrets

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PostPosted: Wed May 16, 2012 9:46 am 
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A242S pedigree

EPI245992 A/duck/Egypt/0982-NLQP/2009 (A/H5N1) segment 4 (HA) 27.0 8.182327e+00 14/14 (100%)
EPI245983 A/duck/Egypt/08355S-NLQP/2008 (A/H5N1) segment 4 (HA) 27.0 8.182327e+00 14/14 (100%)
EPI245981 A/chicken/Egypt/0883-NLQP/2008 (A/H5N1) segment 4 (HA) 27.0 8.182327e+00 14/14 (100%)
EPI127756 A/duck/Egypt/9399NAMRU3-CLEVB202/2007 (A/H5N1) segment 4 (HA) 27.0 8.182327e+00 14/14 (100%)

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PostPosted: Tue Jul 24, 2012 6:57 am 
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Thread on CEIRS meeting in New York

viewtopic.php?f=5&t=8160

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