Figure 3. Detection of antibody responses and evaluation of neutralizing activity for sera of mice vaccinated with truncated HA1.

Sera from 10 days post-last vaccination were used for the detection. (A) Detection of sera IgG antibody responses by ELISA respectively coated with truncated HA1 protein fragments with the serum dilution at 1∶12800. The data are presented as mean A450± standard deviation (SD) of five mice per group. (B) ELISA detection of IgG binding ability to the truncated HA1 protein fragments. The data are presented as mean A450± SD of five mice per group at various dilution points. (C) Neutralizing antibody titers against HA of homologous strain A/Anhui/1/2005(H5N1) (AH-HA, clade 2.3.4) of H5N1 pseudovirus. The data are presented as mean 50% neutralizing antibody titer (NT₅₀) ± SD from five mice per group. * indicates significant difference (P<0.05) between HA-13–263-Fdc vaccination group and other groups.