Figure 5.

Profiling of RBD-specific CD4⁺ T cell responses

(A) CD4⁺ T-cell frequencies specific for RBD variants in T1 (n = 27) and T4 (n = 33). The Friedman test followed by the Dunn multiple comparison test was performed, and no significant differences were observed (p > 0.05).

(B) Correlation between S- or RBD variant-specific CD4⁺ T cell frequencies and anti-RBD IgG titers. The Spearman rank correlation coefficient was used for statistical analysis. The lines in the figures represent the best fit curve of simple linear regression analyses. Red characters indicate R ≥ 0.4 with statistical significance (∗∗p < 0.01).