FIG 2.

Distinctive amino acid variations in HA and NA of HP-H7N9 compared to LP-H7N9. The amino acid sequences of HA and NA were aligned between HP-H7N9 and the consensus sequences of LP-H7N9. The specific residues in HA and NA are listed. “X” of A/GX/18902/2017 at site 235 indicates an H or L residue, and “X” of A/GD/17SF064/2017 at site 289 indicates a K or R residue. The numbers in brackets represent the numbers of HP-H7N9 strains. CK, chicken; DK, duck; EN, environment; GD, Guangdong; GX, Guangxi; HuN, Hunan; HY, Heyuan; HZ, Huizhou; SZ, Shenzhen.