Figure 1
Antigen-specific IgG response and HI titre in chickens with intramuscular administration of inactivated H9N2 and/orB. subtilisspores. A Scheme of the immunization schedule. One-week-old White Leghorn chickens (N = 5) were administered with PBS as a negative control, 2 × 109 CFU of B. subtilis spores, or inactivated H9N2 without or with B. subtilis spores. B The antigen-specific IgG antibody response in serum was measured and expressed as arbitrary units at 3 and 4 weeks. C HI assays with sera against H9N2 virus at 4 weeks. To determine the significance, one-way ANOVA followed by a Friedman test corrected by Dunn’s multiple comparison test was performed. Data are expressed as the mean values ± SDs. Different letters on each group denote a significant difference at P ≤ 0.05.