Antigen-specific antibody responses and HI titer in MN or IN-immunized sera with 1 μg.

<p>Antigen-specific antibody responses at week 4 (IgG—A, IgG1—B and IgG2a—C) and HI titer (D) at week 2 and week 4 in mice sera immunized by IN or MN vaccination. Mice sera injected by MN or IN immunization were collected biweekly and measured for their HI titer and IgG, IgG1 and IgG2a levels by HI assay and ELISA. n = 11 for HI titer and n = 5 for antibody titer. Error bars represent standard errors. *, p<0.05; **, p<0.005; ***, p<0.001. n.s, not significant.