Figure 2.

Immunogenicity of aerosolized YF-17D in A129 mice (A) Schematic diagram of the experimental design. Briefly, groups of 6~8-week-old A129 mice (n = 6) were immunized with 10⁴ PFU of YF-17D or aerosolized YF-17D, respectively. Then, sera samples at 14, 21 dpi were collected for total YFV-specific IgG antibody (B) and IgA antibody (C) titers by ELISA, and neutralizing antibody (nAb) (D) titers by PRNT, respectively. IgG and IgA antibody titers were calculated according to the highest dilution that resulted in a value two-fold greater than the absorption of the control serum. (E) SIgA antibody in BAL of YF-17D-immunized mice (n = 5) at 21 dpi were measured by ELISA. The positive cutoff is twice the average of the negative control group. The data were shown as mean ± SD. Significance was calculated using unpaired t-test (n.s., not significant).