Fig. 3

Evaluation of immunity and production of specific IgG in mice. A Mouse study design. The mice were immunized subcutaneously or muscularly at 0, 2 and 4 weeks, and blood was taken beforehand. Mice injected with ferritin and PBS were used as the negative control group. B Using commercially synthesized peptides as antigens, the titre of specific IgG in the serum was detected by ELISA. C The purchased haemagglutinin protein was used as the coating antigen, and the antibody titre in serum was detected by ELISA. D Synthetic peptides and commercial CDV haemagglutinin proteins were used as antigens to detect the serum titre by ELISA. Comb stands for combined immunization. ^##P < 0.01, ^***P < 0.001, ^###P < 0.001