TABLE 1.

Set of influenza A virus strains included in the study

Coverage periodSubtypeStrain
1968-1975H1N1A/PR/8/34
H3N2A/Hong Kong/1/68
1976-1986H1N1A/USSR/90/77
H3N2A/Bangkok/1/79
1987-1989H1N1A/Taiwan/1/86
H3N2A/Leningrad/360/86
1989-1998H1N1A/Texas/36/91
H3N2A/Beijing/353/89
1999-2004H1N1A/New Caledonia/20/99
H3N2A/Panama/2007/99
Additional strainsH1N1A/WS/33
A/Brevig Mission/1/18
H2N2A/Japan/305/57
A/Taiwan/1/64
H3N2A/Udorn/307/72
A/New York/5/2004
H5N1A/Viet Nam/1194/2004
A/Hong Kong/156/97
H6N1A/teal/HK/W312/97
H7N7A/Chicken/Germany/R28/03
A/Chicken/Netherlands/1/03
H9N2A/Hong Kong/1073/99
A/Hong Kong/1074/99