Fig. 4.

Microneutralization assays against the variants. Graphs represent the percentage of SARS-CoV-2 inhibition of infection vs. the reciprocal dilution of the sera. The first dilution is 1/10, follow by a series of 1/3 dilution. Neutralization of SARS-CoV-2 Alpha (B1.1.7) infection using sera from mice immunized once (A) or twice (B) with RBD-PapMV, RBD + PapMV or Buffer. (C) MNA against the Delta variant. (D) MNA against the Omicron variant. Statistical differences between the RBD-PapMV and the buffer groups are showed in grey (*) while differences between RBD-PapMV and the RBD + PapMV are shown in blue (*). *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.