TABLE 2

Agglutination of TRBCs by viruses with wild-type or mutant HAsa

AntigenHA titer
TRBCVCNAα2,3-TRBCα2,6-TRBC
A/Netherlands/602/095120032
127DT mutant1280032
153KE mutant1280164
155GE mutant5120116
156ND mutant51202128
156NG mutant256004
156NS mutant256002
156NY mutant640032
224EA mutant1280064
152VT156NS mutant128008
155GE224EA mutant1,024001,024
A/Vietnam/1194/200412802560
A/Netherlands/213/200325600256
  • a Hemagglutination titers are expressed as the HAU with unmodified TRBCs, TRBCs stripped from SAs using VCNA, or TRBCs resialylated to contain either α2,3- or α2,6-SA. A/Vietnam/1194/2004 and A/Netherlands/213/2003 served as typical avian and human viruses with α2,3- and α2,6-SA preferences, respectively.