Fig. 6.
Detecting antigenic variants of H3N2 historical seasonal influenza viruses. JO/33, NA/933, SY/05, BR/10, PE/16, VI/361 representing antigenic cluster BE92, WU95, SY97, BR07, PE09, and VI11, respectively. The homologous polyPLA titers were significantly higher than the heterologous titers for both the antigenic drift event BE92>WU95>SY97 (A) and BR07>PE09>VI11(B). These results were consistent with those measured from conventional HI and neutralization assays (Tables 2 and 3).