Table 3.

Virus receptor binding specificity of the avian H6N1, avian H9N2 and human H1N1 influenza viruses

Virus	HA titers with normal chicken RBCs	HA titers with α-2,3 specific-neuraminidase-treated chicken RBCs	HA titers with sheep RBCs	Receptor specificity
ZJ-1664(H6N1)	256	32	256	α2,3-SA and α2,6-SA binding
ZJ-1667(H6N1)	256	32	256	α2,3-SA and α2,6-SA binding
A/chicken/Zhejiang/329/2011(H9N2)	256	< 2	256	α2,3-SA binding
A/Puerto Rico/8/1934(H1N1)	256	256	< 2	α2,6-SA binding

Note: The HA titer was defined as the reciprocal of the highest virus dilution resulting in the hemagglutination of RBCs. “α2,3-SA” and “α2,6-SA” indicate “α-2,3-linked sialic acids” (avian receptor) and “α-2,6-linked sialic acids” (human receptor), respectively