Fig. 7.

RBD-NVP elicits robust RBD-specific antibody responses in mice. (a) BALB/c mice were vaccinated three times, with 2 weeks intervals between each injection. Blood was sampled on the indicated days. RBD-NVP significantly increased serum antibody titers of RBD-specific (b) IgG, (c) IgG1, and (d) IgG2a, compared to the soluble vaccine. Data are presented as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001, analyzed by two-way ANOVA, followed by Tukey's HSD multiple comparison post hoc test.