J. Aubin, S. Azebi, A. Balish, J. Banks, N. Bhat et al.,

N. Dowell, L. Tien-dung, K. Edwards, R. Fukuda, E. Garten et al., al. Genesis of a highly pathogenic and potentially pandemic H5N1 influenza virus in eastern Asia, pp.5-0644, 2004.

, World Health Organization Confirmed human cases of avian influenza A(H5N1) since 28, 2004.

K. Ungchusak, P. Auewarakul, S. Dowell, R. Kitphati, W. Auwanit et al., Probable Person-to-Person Transmission of Avian Influenza A (H5N1), New England Journal of Medicine, vol.352, issue.4, pp.333-373, 2005.
DOI : 10.1056/NEJMoa044021

I. Wilson and N. Cox, Structural Basis of Immune Recognition of Influenza Virus Hemagglutinin, Annual Review of Immunology, vol.8, issue.1, pp.737-71, 1990.
DOI : 10.1146/annurev.iy.08.040190.003513

R. Welliver, A. Monto, O. Carewicz, E. Schatteman, M. Hassman et al., Effectiveness of Oseltamivir in Preventing Influenza in Household Contacts<SUBTITLE>A Randomized Controlled Trial</SUBTITLE>, JAMA, vol.285, issue.6, pp.748-54, 2001.
DOI : 10.1001/jama.285.6.748

A. Hay, A. Wolstenholme, J. Skehel, and M. Smith, The molecular basis of the specific anti-influenza action of amantadine, EMBO J, vol.4, pp.3021-3025, 1985.

J. Devereux, A comprehensive set of sequence analysis programs for the VAX, Nucleic Acids Research, vol.12, issue.1Part1, pp.387-95, 1986.
DOI : 10.1093/nar/12.1Part1.387

J. Felsenstein, PHYLIP Phylogeny Inference Package Version 3.2, Cladistics, vol.5, pp.164-170, 1989.

A. Kendal, M. Pereira, J. Skehel, A. Kendal, M. Pereira et al., Hemagglutination inhibition Concepts and procedures for laboratory-based influenza surveillance Organization, Atlanta: Centers for Disease Control and Prevention and Pan-American Health, pp.17-35, 1982.

I. Stephenson, J. Wood, K. Nicholson, and M. Zambon, Sialic acid receptor specificity on erythrocytes affects detection of antibody to avian influenza haemagglutinin, Journal of Medical Virology, vol.21, issue.3, pp.391-399, 2003.
DOI : 10.1016/S0264-410X(02)00632-1

B. Mungall, X. Xu, and A. Klimov, Surveillance of influenza isolates for susceptibility to neuraminidase inhibitors during the 2000???2002 influenza seasons, Virus Research, vol.103, issue.1-2, pp.195-202, 2004.
DOI : 10.1016/j.virusres.2004.02.033

E. Fodor, L. Devenish, O. Engelhardt, P. Palese, G. Brownlee et al., Rescue of influenza A virus from recombinant DNA, J Virol, vol.73, pp.9679-82, 1999.

G. Neumann, T. Watanabe, H. Ito, S. Watanabe, H. Goto et al., Generation of influenza A viruses entirely from cloned cDNAs, Proceedings of the National Academy of Sciences, vol.8, issue.5, pp.9345-50, 1999.
DOI : 10.1016/S0958-1669(97)80033-X

E. Hoffmann and R. Webster, Unidirectional RNA polymerase I???polymerase II transcription system for the generation of influenza A virus from eight plasmids, Journal of General Virology, vol.21, issue.12, pp.2843-2850, 2000.
DOI : 10.1093/nar/21.16.3607

R. Webby, D. Perez, J. Coleman, Y. Guan, J. Knight et al., Responsiveness to a pandemic alert: use of reverse genetics for rapid development of influenza vaccines, The Lancet, vol.363, issue.9415, pp.1099-103, 2004.
DOI : 10.1016/S0140-6736(04)15892-3

J. Schickli, A. Flandorfer, T. Nakaya, L. Martinez-sobrido, A. Garcia-sastre et al., Plasmid-only rescue of influenza A virus vaccine candidates, Philos Trans R Soc Lond B Biol Sci, vol.356, pp.1965-73, 2001.

E. Hoffmann, G. Neumann, Y. Kawaoka, G. Hobom, and R. Webster, A DNA transfection system for generation of influenza A virus from eight plasmids, Proceedings of the National Academy of Sciences, vol.96, issue.16, pp.6108-6121, 2000.
DOI : 10.1073/pnas.96.16.9363

C. Nicolson, D. Major, J. Wood, and J. Robertson, Generation of influenza vaccine viruses on Vero cells by reverse genetics: an H5N1 candidate vaccine strain produced under a quality system, Vaccine, vol.23, issue.22, pp.2943-52, 2005.
DOI : 10.1016/j.vaccine.2004.08.054

, World Health Organization Production of pilot lots of inactivated influenza vaccine in response to a pandemic threat: an interim biosafety risk assessment, Wkly Epidemiol Rec, vol.78, pp.405-413, 2003.

K. Subbarao, H. Chen, D. Swayne, L. Mingay, E. Fodor et al., Evaluation of a Genetically Modified Reassortant H5N1 Influenza A Virus Vaccine Candidate Generated by Plasmid-Based Reverse Genetics, Virology, vol.305, issue.1, pp.192-200, 2003.
DOI : 10.1006/viro.2002.1742

, Centers for Disease Control and Prevention. Outbreaks of avian influenza A (H5N1) in Asia and interim recommendations for evaluation and reporting of suspected cases?United States, MMWR Morb Mortal Wkly Rep, vol.53, pp.97-100, 2004.

K. Sturm-ramirez, T. Ellis, B. Bousfield, L. Bissett, K. Dyrting et al., Reemerging H5N1 Influenza Viruses in Hong Kong in 2002 Are Highly Pathogenic to Ducks, Journal of Virology, vol.78, issue.9, pp.4892-901, 2004.
DOI : 10.1128/JVI.78.9.4892-4901.2004

T. Tumpey, D. Suarez, L. Perkins, D. Senne, J. Lee et al., Evaluation of a High-Pathogenicity H5N1 Avian Influenza A Virus Isolated from Duck Meat, Avian Diseases, vol.47, issue.s3, pp.951-956, 2003.
DOI : 10.1637/0005-2086-47.s3.951

Y. Ha, D. Stevens, J. Skehel, and D. Wiley, X-ray structures of H5 avian and H9 swine influenza virus hemagglutinins bound to avian and human receptor analogs, Proceedings of the National Academy of Sciences, vol.74, issue.18, pp.11181-11187, 2001.
DOI : 10.1128/JVI.74.18.8502-8512.2000

S. Baigent and J. Mccauley, Glycosylation of haemagglutinin and stalk-length of neuraminidase combine to regulate the growth of avian influenza viruses in tissue culture, Virus Research, vol.79, issue.1-2, pp.177-85, 2001.
DOI : 10.1016/S0168-1702(01)00272-6

L. Mitnaul, M. Matrosovich, M. Castrucci, A. Tuzikov, N. Bovin et al., Balanced Hemagglutinin and Neuraminidase Activities Are Critical for Efficient Replication of Influenza A Virus, Journal of Virology, vol.74, issue.13, pp.6015-6035, 2000.
DOI : 10.1128/JVI.74.13.6015-6020.2000

M. Perdue and D. Suarez, Structural features of the avian influenza virus hemagglutinin that influence virulence, Veterinary Microbiology, vol.74, issue.1-2, pp.77-86, 2000.
DOI : 10.1016/S0378-1135(00)00168-1

Y. Guan, L. Poon, C. Cheung, T. Ellis, W. Lim et al., H5N1 influenza: A protean pandemic threat, Proceedings of the National Academy of Sciences, vol.77, issue.12, pp.8156-61, 2004.
DOI : 10.1128/JVI.77.12.6988-6994.2003

C. Bender, H. Hall, J. Huang, A. Klimov, N. Cox et al., Characterization of the Surface Proteins of Influenza A (H5N1) Viruses Isolated from Humans in 1997???1998, Virology, vol.254, issue.1, pp.115-138, 1997.
DOI : 10.1006/viro.1998.9529

M. Matrosovich, N. Zhou, Y. Kawaoka, and R. Webster, The surface glycoproteins of H5 influenza viruses isolated from humans, chickens, and wild aquatic birds have distinguishable properties, J Virol, vol.73, pp.1146-55, 1999.

I. Leneva, N. Roberts, E. Govorkova, O. Goloubeva, and R. Webster, The neuraminidase inhibitor GS4104 (oseltamivir phosphate) is efficacious against A, H9N2) influenza viruses, pp.101-116, 1074.

K. Subbarao, Influenza Vaccines: Present and Future, Adv Virus Res, vol.54, pp.349-73, 1999.
DOI : 10.1016/S0065-3527(08)60371-1

E. Kilbourne, Future influenza vaccines and the use of genetic recombinants, Bull World Health Organ, vol.41, pp.643-648, 1969.

E. Hoffmann, S. Krauss, D. Perez, R. Webby, and R. Webster, Eight-plasmid system for rapid generation of influenza virus vaccines, Vaccine, vol.20, issue.25-26, pp.3165-70, 2002.
DOI : 10.1016/S0264-410X(02)00268-2

J. Keawcharoen, K. Oraveerakul, T. Kuiken, R. Fouchier, A. Amonsin et al., Avian Influenza H5N1 in Tigers and Leopards, Emerging Infectious Diseases, vol.10, issue.12, pp.2189-91, 2004.
DOI : 10.3201/eid1012.040759

R. Harvey, A. Martin, M. Zambon, and W. Barclay, Restrictions to the Adaptation of Influenza A Virus H5 Hemagglutinin to the Human Host, Journal of Virology, vol.78, issue.1, pp.502-509, 2004.
DOI : 10.1128/JVI.78.1.502-507.2004

M. Mase, K. Tsukamoto, T. Imada, K. Imai, N. Tanimura et al., Characterization of H5N1 influenza A viruses isolated during the 2003???2004 influenza outbreaks in Japan, Virology, vol.332, issue.1, pp.167-76, 2005.
DOI : 10.1016/j.virol.2004.11.016

T. Kuiken, G. Rimmelzwaan, D. Van-riel, G. Van-amerongen, M. Baars et al., Avian H5N1 Influenza in Cats, Science, vol.306, issue.5694, p.241, 2004.
DOI : 10.1126/science.1102287

R. Thanawongnuwech, A. Amonsin, R. Tantilertcharoen, S. Damrongwatanapokin, A. Theamboonlers et al., Probable Tiger-to-Tiger Transmission of Avian Influenza H5N1, Emerging Infectious Diseases, vol.11, issue.5, pp.699-701, 2005.
DOI : 10.3201/eid1105.050007

O. Address-for-correspondence:-ruben, I. Donis, . Branch, . Dvrd, and . Ncid, , pp.16-1600

C. Rd and . Atlanta, , pp.404-639