Fig. 4: T cell polyfunctionality and correlation analysis.

a Polyfunctionality of antigen-specific CD4⁺ T cells (CD154⁺ or TNF-α⁺ or IL-2⁺ or IFN-γ⁺ and IL-2⁺/TNF-α⁺ or IFN-γ⁺/TNF-α⁺ or IFN-γ⁺/IL-2⁺ and IFN-γ⁺/IL-2⁺/TNF-α⁺) in the total CD4⁺ T cell population at day 7 post exposure. PBMCs were stimulated overnight with SARS-CoV-2 S1, S2, RBD or N overlapping peptide pools. Each intersection on the radar charts is separated by 0.025. b Correlation matrix between humoral, cellular and virological parameters. Spearman r values from -0.7 to -1 and 0.7 to 1 are visible. c Correlation between ELISpot IFN-γ-secreting cells upon ex vivo overnight stimulation with SARS-CoV-2 S1 overlapping peptide pools and neutralizing antibody titers to SARS-CoV-2 at week 5 p.im. (w5); Correlation between IgG binding to SARS-CoV-2 S protein and neutralizing antibody titers to SARS-CoV-2 at w5 p.im. In panels a and c, Control group is in black, High dose group is in blue and Medium dose group is in orange. In (c), each animal is identified by distinct symbols (Supplementary Table 1 for matching symbols).