Fig. 2.

Serum Neutralizing Antibody Response and Cross-Reactivity Comparisons of AS03-Adjuvanted CoVLP or CoVLP.B1351 Following Homologous Prime-Boost Regimen. BALB/c mice (n = 8) were immunized IM on Days 0 and 21 with 3.75 µg of CoVLP or CoVLP.B1351 formulated with AS03 adjuvant. NAb titers were measured against SARS-CoV-2 pseudoparticles in serum samples using a cell-based PNA targeting the ancestral or B.1.351 strains. Half of the minimum required dilution (MRD) of the method was assigned to non-responders (i.e. 12.5). (A) GMT with 95 % CI measured 21 days after the 1st immunization (Day 21) and 14 days after the 2nd immunization (Day 35). Statistical comparisons were performed using a two-way ANOVA followed by a Bonferroni post hoc test on log₁₀-transformed NAb titers. (B-C) Results from individual mouse serum samples (n = 8 per antigen) are represented as dots on each figure with lines connecting ancestral of B.1.351 to the B.1.351, B.1.1.7, P.1, B.1.617.2 or B.1.1.529 neutralization titers. Statistical comparisons were performed using Wilcoxon matched pairs signed rank test. p-values are indicated on the graphs. ns: Not significant (p > 0.05).