FIG 2 .

Cross-reactive antibody response to HAs from emerging Eurasian and American lineage H7 viruses after H7 A/Anhui/1/2013 vaccination as measured by ELISA. (A) Serum samples from a subselection of samples (high-dose 30-µg recombinant HA adjuvanted group) were tested for binding to H7 HAs of different H7NX virus isolates (H7N9 A/Hunan/02285/2017, H7N9 A/Hong Kong/2014/2017, H7N9 A/Guangdong/17SF003/2016, H7N2 A/feline/New York/16-040082-1/2016, and H7N8 A/turkey/Indiana/16-001403-1/2016). Absolute ELISA area under the curve (AUC) values were determined. Data for baseline (D0, white) and postvaccination (D42, red) serum samples are shown. The dashed lines represent the GM titer of serum antibodies binding to A/Anhui/1/2013 at day 0 (gray line) and day 42 (black line) as shown in Fig. 1C. (B) Fold induction of cross-reactive H7 antibodies based on ELISA AUC values postvaccination (D42). The dashed line represents the induction based on the ELISA AUC values of serum antibodies binding to A/Anhui/1/2013 as shown in Fig. 1D. Time points day 0 and day 42 were compared within each treatment group in a one-way ANOVA. Significance is indicated as follows: no symbol, P > 0.05; *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001; ****, P ≤ 0.0001.