Figure 2.

Hemagglutinin inhibition titer for select escape viruses. HAI titers for Victoria lineage viruses (A) and Yamagata lineage viruses (B) are shown. Viruses are labeled in the legend as for Table 1 and Table 2. The data for the CO/WT and PK/WT viruses (from Table 1 and Table 2) are shown as the green and blue bars in panels A and B, respectively. Graph bars are colored to indicate the predominance of B/CO-like (green) or B/PK-like (blue) amino acids at positions highlighted in Figure 1. Red stripes indicate changes to the 120- and 150-loops; and red dots indicate the G141R change. Graph bars with a black outline indicate that the virus was generated using the sera indicated in that column.