Figure 1

Amino acid comparison at the HA domains of H3N2 influenza viruses. Dots denote amino acids similar to the consensus, and squares denote conserved amino acid residues at the receptor-binding site. The asterisk denotes ZJ-SW19. N-glycosylation sites are presented in boxes. Amino acid residues mapped at previously defined antigenic sites A, B, C, D, and E are presented in blue, purple, yellow, pink, and green, respectively.