Figure 3.

Binding motifs of H3N2 viruses. The minimal motifs bound by 2003–2005 H3N2 viruses (A) and A/Philippines/2/82/X-79 (B). Recent viruses require a minimum of 3 sugars to bind while Philippines binds a disaccharide. It can accommodate an N-glycolyl in place of N-acetyl on the terminal sialic acid.