Composition of the hemagglutinin receptor binding amino acids and residues that interact with α2-3 and α2-6 glycans.

Consensus sequences from human H2N2 viruses that circulated during pandemic, H2N2 avian viruses and from the viruses used in this study.
*More than one amino acid is shown in cases where the proportion of viruses containing it was higher than 30%.
**Receptor binding amino acids 226Q228G and 226Q228S could be found in the viruses that circulated during this period.