Fig. 4.

Antibody response in serum. BALB/c mice (n = 6/group) were immunized s.c. with 10 μg of Flg-HA2–2-4M2ehs, or FlgSh-HA2–2-4M2ehs on days 0, 14, 28. Control groups mice were administered with FliC (10 μg) and PBS. Two weeks post second boost, M2e-specific IgG responses (a) and FliC-specific IgG responses (b) were evaluated by ELISA. c Anti-M2e IgG subclasses tested against M2e peptide in serum, 2 weeks post second boost, were determined by ELISA. d Titers of serum IgG to influenza viruses A/H7N9, A/H3N2, A/H1N1pdm09, A/H5N1. Data are presented as the geometric mean titers (GMT) with 95% CI (confidence interval). Statistical significance was determined using Mann-Whitney U-test. The P values between immunized and control group are indicated. *significant difference from control groups, p < 0.01