UNCLASSIFIED
Avian Influenza Daily Digest
October 24, 2008 14:00 GMT
This digest is produced by the United States Government, Office of the Director of National Intelligence, Washington DC, USA. Articles and resource documents in this digest are from open sources and unclassified.
This digest contains raw open source content and is not an evaluated intelligence product. Readers are encouraged to contribute updates and/or clarifications that will be posted in subsequent issues of the digest. Articles may contain copyrighted material, further dissemination outside government channels may be prohibited without permission from the copyright owners.
Please note some links may only work while connected to the Intelink network.
Unsubscribe/Subscribe to the AI Digest
Contact AI Digest Editor/Contribute (U) Information
Contribute (U) Updates/Clarifications to a previously reported article
Contribute (U) Information anonymously
View 30-Day HPAI H5N1 outbreak data in Google Maps
Intelink Avian Influenza Resources:
U.S. Govt. IC: Intelink AI/Pandemic page https://www.intelink.gov/mypage/avianflu
Article Summaries ...
Quid Novi
Germany: HPAI reported in Saxony
Regional Reporting and Surveillance
MEP raises concerns over EU poultry meat imports from China
10/24/08 First4farming--MEP Jim Allister has expressed concerns over the rigour of health checks carried out prior to the lifting of an import ban on poultrymeat from China.
Regional Reporting and Surveillance
Science and Technology
Vaxart Demonstrates Efficacy of Oral Avian Flu Vaccine in Preclinical Studies
10/24/08 Vaxart Inc., a biotechnology company focused on the development of oral vaccines, today announced positive efficacy results from preclinical studies of the company's oral avian flu vaccine. Sean Tucker, PhD, Vaxart founder and vice president of research, presented data from animal models demonstrating that an orally administered flu vaccine was protective against lethal exposure to H5N1 influenza. Tucker presented the data this morning at the Modern Mucosal Vaccines, Adjuvants & Microbicides (MMVAM) international conference in Porto, Portugal.
Vaccines
Full Text of Articles follow ...
Quid Novi
Germany: HPAI reported in Saxony
10/24/08 ProMed--Highly pathogenic avian influenza virus H5N1 has been detected in
clinically healthy ducks in a mixed poultry holding in Saxony,
Germany. 30 oropharyngeal swabs from geese and ducks had been sampled
for routine monitoring purposes. A single duck tested positive for
HPAIV H5N1, and the cleavage site sequence was confirmed as
GERRRKKR*GLF on 9 Oct 2008. Subsequently, 157 additional duck samples
were obtained and revealed a further 24 H5N1 positives, of which 9
had sufficient viral loads to be confirmed as HPAIV. All poultry were
culled. No more cases have been detected up to now in contact farms
or in wild bird samples obtained from this region.
Preliminary sequence and phylogenetic analysis of the HA gene from 4
duck samples gave evidence for a representative of a cluster 2.2
sublineage which had been detected in spring 2006 in Southern
Germany. In fact, a virus from a tufted duck (R1240/06; Starick et
al., 2008) found in 2006 40 km away from the present outbreak
location is very closely related. So far, there are no records for
the presence of viruses of this sublineage after May 2006 in Germany
and Europe. In summary, the data suggest a very recent introduction
of HPAIV H5N1 into this farm from an as yet unknown source.
In parallel, LPAIV H5 infections have been detected in waterfowl in
the zoo of Leipzig, Saxony and in a small mixed poultry holding near
Leipzig. These viruses turned out to be typical representatives of
Eurasian H5 LPAIV currently also detected in aquatic wild birds in
Germany. Poultry at the LPAIV-affected holdings had been culled as
well.
[Elke Starick (Senior Scientist, OIE and National Reference
Laboratory AI) Dr. Christian Grund (Deputy Head OIE and National
Reference Laboratory AI) Dr. Timm Harder (Head OIE and National
Reference Laboratory AI) Dr. Martin Beer (Head Institute of
Diagnostic Virology, Friedrich-Loeffler-Institut) Prof. Dr. Thomas C.
Mettenleiter (President, Friedrich-Loeffler-Institut)]
--
Communicated by:
Dr. Martin Beer
Head Institute of Diagnostic Virology
Friedrich-Loeffler-Institut
Am Suedufer 10
17493 Greifswald-Insel Riems
Germany
Vaccines
Vaxart Demonstrates Efficacy of Oral Avian Flu Vaccine in Preclinical Studies
10/24/08 Vaxart Inc., a biotechnology company focused on the development of oral vaccines, today announced positive efficacy results from preclinical studies of the company's oral avian flu vaccine. Sean Tucker, PhD, Vaxart founder and vice president of research, presented data from animal models demonstrating that an orally administered flu vaccine was protective against lethal exposure to H5N1 influenza. Tucker presented the data this morning at the Modern Mucosal Vaccines, Adjuvants & Microbicides (MMVAM) international conference in Porto, Portugal.
Delivery of flu vaccine via a capsule rather than an injection offers critical advantages, particularly in the case of a pandemic. The Vaxart vaccine formulation can withstand ambient temperatures, enabling emergency distribution methods that avoid the transmission risks associated with centralized vaccination clinics. In the developing world, where medical providers and supplies are scarce, oral vaccination will reduce costs, as well as needle reuse and consequent cross-infection.
The data presented today are from studies measuring the effectiveness of an orally-administered avian flu vaccine designed by Vaxart scientists using the company's proprietary modular platform. The Vaxart vaccine (ND1) comprises a non-replicating chimeric adenovirus-5 vector, or delivery vehicle, engineered to express avian flu hemaggluttinin (HA) and a TLR3 ligand as a vaccine adjuvant.
"Injected vector-based vaccines that deliver a target pathogen protein have shown excellent potency in animal models, but their application has been limited in humans because the immune system typically responds to the vector rather than the target," said Dr. Tucker. "By using oral delivery of a non- replicating vector with a potent adjuvant, we achieve a robust immune response that is focused on the targeted pathogen rather than the delivery vehicle. This approach addresses the problems that have plagued vector-based vaccination and also allows us to create different vaccines simply by switching out the antigen."
In the recent study, Vaxart tested the ND1 vaccine using oral administration to ferrets, widely recognized as the most predictive animal model for influenza research. Researchers administered vaccine at the start of the study and at 4 weeks. At 8 weeks, researchers measured antibody responses, then monitored survival following direct nasal exposure of 10 times the median lethal dose of H5N1 avian influenza virus. Seventy-five percent (6 of 8) of oral vaccinated ferrets developed antibody levels of 1:200 or greater, survived the challenge and were healthy as demonstrated by weight gain after challenge, while all 12 control ferrets either died (67 percent) or became very ill (33 percent). These results, if confirmed in human immunogenicity studies, compare well to the approved, injectable avian flu vaccine that achieved protective antibody levels in 45 percent of human subjects.
In a previous study conducted in mice, 6 of 6 mice vaccinated orally with ND1 survived H5N1 avian flu challenge, while 8 of 8 unvaccinated mice died. Based on these results, Vaxart plans to proceed to an investigational new drug application (IND) and begin clinical studies of the avian flu vaccine in 2009. The company is also developing an annual flu vaccine.
"To date, efforts to develop a broadly-applicable oral vaccine platform have not been successful, but the advantages of a modular approach for vaccine development are compelling, particularly for influenza," said Mark Backer, PhD, Vaxart CEO. "We can provide a vaccine that matches a new outbreak strain months faster than current approaches."
"These results are encouraging. An oral vaccine for pandemic flu would be a great help in rapid distribution to large numbers of people," said Dr. Arnold Monto, professor of epidemiology at University of Michigan. "The availability of an oral vaccine for annual influenza would also likely improve vaccination compliance and help reduce the rates of hospitalization and death that are associated with flu every year."
The Vaxart Approach
Vaxart has developed a proprietary, modular approach to vaccine development that will reduce the time and expense needed to bring new vaccines to market. The key to Vaxart's efforts is a unique adjuvant (an adjuvant is the vaccine component that enhances immune response to a foreign protein). Vaxart uses an adjuvant that works through a "toll-like receptor" (TLR). Vaxart determined that TLR3 is much more active in the gut than other TLR pathways that have been used for injected vaccines, making this the only TLR adjuvant approach likely to work well for oral vaccines. The company has demonstrated both the induction of mucosal immunity and the stimulation of antigen-specific cell-based immunity following oral administration of its vaccines; these features may provide a performance advantage over injected protein vaccines.
Another key feature of the Vaxart platform is the ability to employ the same vector (delivery vehicle) across all vaccines. Typically an injected vector can only be used once, because antibodies build up against the vector proteins after initial exposure. Subsequent vaccines are less effective, because the body neutralizes the vector before a response can be mounted against the disease target. Vaxart has overcome this obstacle and demonstrated that strong immune responses can be generated against multiple diseases following a series of different oral vaccines. Vaxart will be able to produce new vaccines through a standardized and low-cost process, and safety data from one vaccine will be supportive for others created through the platform.
Regional Reporting and Surveillance
MEP raises concerns over EU poultry meat imports from China
10/24/08 First4farming--MEP Jim Allister has expressed concerns over the rigour of health checks carried out prior to the lifting of an import ban on poultrymeat from China.
Imports of poultrymeat from China to the EU were banned in 2002 because of avian flu. However, in July 2008, the EU agreed to re-admit treat-heated poultrymeat from Shandong Province, on the basis that it now met EU health and welfare standards.
Against this background, Mr Allister has been pressing Commission vice-president Siim Kallas as to just how rigorous the EU had been in allowing itself to be persuaded to re-start imports from China.
While Commissioner Kallas stressed that public health rules applying to these exports from China ensured an equivalent level of protection to those in the EU, there are concerns over the checks made.
It turns out that exports to the EU have been recommenced on the basis of just three fact-finding missions, the most recent being back in 2006, said Mr Allister.
Here we are opening our market in the latter half of 2008 on the basis of stale inspections and with no further inspection intended until 2009. This is not what I believe EU consumers would expect, he said.
But when I pressed the Commissioner further I was disappointed to get no answer to three critical questions. First, imports are only supposed to come from plants in Shandong Province - how do we know that the imported meat in fact all originates there? Second, will there be the same ratio of production tested for EU health standards as would apply within the EU in our own plants, or are we relying on self-certification?
Finally, for welfare, will the same requirements be placed on China as we are imposing on our own producers?
Sadly, the Commissioner was unable to answer these questions, suggesting to me that once more, with echoes of what happened with Brazilian beef, we are going down the road of allowing imports without them transparently meeting the same rigorous requirements that we place on our own produce. This is unfair to both producers and consumers in the EU, said Mr Allister.
