Table 1.

Clustered substitutions observed for H3N2 strains considered in this study, classified by the regions in which the clusters occur

Region	Amino acid identifiers
RBS	62, 75, 78, 80, 82, 83, 94, 96, 121, 122, 124, 126, 131, 133, 135, 137, 138, 139, 142, 143, 144, 145, 146, 155, 156, 157, 158, 159, 160, 163, 164, 182, 185, 186, 188, 189, 190, 192, 193, 194, 196, 197, 199, 201, 202, 207, 208, 213, 214, 216, 217, 219, 222, 223, 225, 226, 227, 233, 242, 244, 248
Midregion	47, 50, 53, 54, 57, 62, 63, 82, 83, 172, 174, 260, 262, 275, 276, 278, 299, 308
Both	62, 82, 83