Skip to main content
. 2023 Feb 14;8:18. doi: 10.1038/s41541-023-00610-4

Fig. 3. Immunization with RBD nanoparticles induce robust SARS-CoV-2 neutralizing titers in mice at all doses tested.

Fig. 3

3-month-old BALB/c mice were injected with PBS or immunized with the indicated doses (0.3, 1, or 3 µg) of RBD, Spike, or RBD nanoparticle (RBD-NP) alone or formulated with AddaVax on Day 0 (prime) and 14 (boost). Serum levels of anti-RBD neutralizing antibodies were assessed on Day 28 by SARS-CoV-2 surrogate (a) and conventional (b) virus neutralization tests. The dotted line indicates a lower limit of detection. N = 7–10 mice per group. * and ** respectively indicate p < 0.05 and 0.01 for comparisons among RBD, Spike, and RBD-NP in the same adjuvant formulation group (− AddaVax or + AddaVax). ## indicates p < 0.01 for comparisons of the same antigen groups between the two adjuvant formulation groups (− AddaVax vs. + AddaVax). Statistical significance was determined by two-way ANOVA corrected for multiple comparisons. Data shown in b were Log-transformed before the analysis. The color code indicates comparisons among experimental groups. Box-and-whisker plots represent the minimum, first quartile, median, third quartile, and maximum value. Each symbol represents an individual mouse. Source data are provided as Supplementary Data.