Figure 4. Vaccine-elicited antibody responses in rabbits immunized with monohead and trihead nanoparticles.

(A) Hypervariable trihead nanoparticle rabbit immunization schedule and groups.
(B–D) ELISA binding titers(B), HAI titers (C), and microneutralization titers (D) in immune sera at week 6.
(E) Microneutralization titers at week 22.
Each symbol represents an individual animal, and the geometric mean of each group is indicated by the bar (n = 5 rabbits/group). Statistical significance was determined using one-way ANOVA with Tukey’s multiple comparisons test; *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001.