Figure 4. Different types of antibody responses were elicited by BPZE1 and aPV immunization.

(A) Immunization schedule for BPZE1 vaccinees (n = 12) and aPV vaccinees (n = 12). (B–D) Antibody titers of IgG, IgA, and 4 IgG subclasses directed against BPZE1 lysates, BP611-98 lysates, and antigen mix in BPZE1 and aPV vaccines were evaluated. OD value is shown. Two-tailed Wilcoxon matched-pairs signed-rank test was used for comparison in the same group. Two-tailed Mann-Whitney test was used for comparison between 2 groups. (E) Antibody avidity of IgG and IgA targeting BPZE1 lysates in BPZE1 and aPV vaccines was evaluated. Avidity index EC50 represents the concentration of chaotropic agent (NH₄SCN) that dissociates 50% of the antibody-antigen binding. Two-tailed Mann-Whitney test was used. (F) Ratio of IgG3/IgG2, IgG4/IgG3, and IgG4/IgG1 against BPZE1 lysates at 28 days after vaccination in BPZE1 and aPV vaccinees is shown. Mann-Whitney test was used. *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001.