TABLE 4.

Amino acid changes in HA of the H5N1 viruses

HA phylogenyVirusAmino acid at positiona:
125129133142144145158159160163166178185193
120124129138140141154155156159162174181189
Clade 1A/Vietnam/1203/04SSLQKSNSTTRVPK
A/Vietnam/1194/04SSLQKSNSTTRVPK
A/Hong Kong/213/03 N SLQKSN N A TRVP R
Clade 2A, subclade 1A/Chicken/Indonesia/PA/03S D S QKSNS A TRVP R
A/Chicken/Malang/BBVet-IV/04S N S QKSNS A TRVP R
A/Chicken/Jogjakarta/BBVet-IX/04S D S L R SNST I RVPK
Clade 2E, subclade 2A/Whooper swan/Mongolia/244/05S D S Q R S D N A TRVP R
Clade 2F, subclade 3A/Duck/Laos/3295/06S D S Q T P N N TTR I SK
  • a Amino acid numbering in the top row is based on H3 HA. Amino acid numbering in the bottom row is based on H5 HA. Amino acid substitutions with respect to the HA of A/Vietnam/1203/04 (H5N1) are indicated in boldface. Amino acid positions changed in the HA of escape mutants are indicated in italics.