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Volume 11, Number 10—October 2005


Evolution of H5N1 Avian Influenza Viruses in Asia

The World Health Organization Global Influenza Program Surveillance Network

Main Article

Table 1

Amino acid differences among H5 hemagglutinins (HA1)

Clade 3 Clade 2 Clade 1´ Clade 1 H3 No. Functional significance
N45* D D D 54† Antigenic site C
S84 N N N 92 Antigenic site E
A86 A A V 93 Antigenic site E
N94 D D D (1) 101 Near Y91; receptor binding?
N124 D S S 129 Antigenic site B
S129 S L L 133a Receptor binding
L138 Q Q Q 142 Antigenic site A
S155 N155 159 Antigenic site B
T156‡ A A T 160 N154 glycosylation motif
L175 L L L (2) 179 Near H179; receptor binding?
T188 T T T (3) 192 Near L190; receptor binding?
K189 R R K 193 Adjacent to receptor binding, antigenic site B
E212 K K R 216 Antigenic site D
S223 N223§ – (4) 227 Receptor binding
T263 A A T 266 Antigenic site E
325R¶ Absent Absent HA cleavage efficiency

*Amino acid residue in single-letter code and position in the mature H5 HA1.
†Equivalent residue number in the mature H3 HA1 aligned with H5 amino acid sequence; –, no change from HK97 clade HA consensus.
‡A156 or S156 were found in certain clade 3 HAs; A156 was present in some HAs from clade 2. HA genes from »50% of isolates collected in 2005 had these substitutions present in only one isolate: 1) to N or V; 2) to M or I; 3) to A, V, or I; or 4) to N.
§Change present exclusively in isolates from humans.
¶Arginine at the start of the polybasic cleavage site, position 325.

Main Article

1Members of the World Health Organization Global Influenza Program and collaborating laboratories: Jean-Thierry Aubin, Saliha Azebi, Amanda Balish, Jill Banks, Niranjan Bhat, Rick A. Bright, Ian Brown, Philippe Buchy, Ana-Maria Burguiere, Hua-lan Chen, Peter Cheng, Nancy J. Cox, Alice Crosier, Aaron Curns, Frédérique Cuvelier, Guohua Deng, Julia Desheva, Stéphanie Desvaux, Nguyen Hong Diep, Ruben O. Donis, Alan Douglas, Scott F. Dowell, Nguyen Tien Dung, Lindsay Edwards, Keiji Fukuda, Rebecca Garten, Elena Govorkova, Victoria Gregory, Alan Hampson, Nguyen Thi Hong Hanh, Scott Harper, Alan Hay, Erich Hoffmann, Diane Hulse, Masaki Imai, Shigeyuki Itamura, Samadhan Jadhao, Patricia Jeannin, Chun Kang, Jackie Katz, Jae-Hong Kim, Alexander Klimov, Yong-kuk Kwon, Chang-Won Lee, Phuong Song Lien, Yanbing Li, Wilina Lim, Yi Pu Lin, Stephen Lindstom, LaMorris Loftin, Jan Mabry, Le Quynh Mai, Taronna Maines, Jean-Claude Manuguerra, Masaji Mase, Yumi Matsuoka, Margaret McCarron, Marie-Jo Medina, Doan Nguyen, Ai Ninomiya, Masatsugu Obuchi, Takato Odagiri, Malik Peiris, Michael L. Perdue, Jean-Marc Reynes, James Robertson, Claudine Rousseaux, Takehiko Saito, Somchai Sangkitporn, Michael Shaw, James M. Simmerman, M. Slomka, Catherine Smith, San Sorn, Erica Spackman, Klaus Stöhr, David L. Suarez, Haan Woo Sung, David E Swayne, Maryse Tardy-Panit, Masato Tashiro, Pranee Thawatsupha, Terrence Tumpey, Timothy Uyeki, Phan Van Tu, Sylvie van der Werf, Sirenda Vong, Richard Webby, Robert Webster, John Wood, Xiyan Xu, Guan Yi, and Wenqing Zhang. For author affiliations, please Download PDF (37 KB, 2 pages).

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