Fig. 2
Post-vaccination sera binding to native HA0, HA1, and HA2 domains. a–j Steady-state equilibrium analysis of human vaccine sera pre-vaccination (D0) and post-vaccination (D28) against properly folded homologous H1N1pdm09 HA0 (a, f), HA1 (b, g), and HA2 (c, h) domains, and H3N2 HA1 (d, i), and B-HA1 (e, j) are measured using SPR. Recombinant HA0, HA1, and HA2 domains are immobilized on a sensor chip through the free amine group. Binding of the polyclonal serum antibodies to the immobilized protein is shown as resonance unit (RU) values for individual subjects receiving FluBlok (in blue), FluCelvax (in red), and Fluzone (in green) for each subject (excluding repeat vaccinators) in year 1 (2015–2016; D0, D28, and D180; a–e) and year 2 (2016–2017; D0 and D28; f–j) of the study. For Day 28 post-vaccination resonance units (RU), and fold change from Day 0, an ANCOVA model was used for comparison between the vaccine groups, adjusted for gender, age, and baseline (Day 0) values (Supplementary Tables 4 and 5). Statistically significant differences between groups and pairs are indicated by horizontal bars. Source data are provided as a Source Data file
