Fig. 6: Multifunctional cytokine analysis of SARS-CoV-2 S-specific CD4⁺ and CD8⁺ T cells in immunized mice.

a Groups of mice (n = 6/group) were immunized with 10 μg NVX-CoV2373 with and without 5 μg Matrix-M adjuvant in two doses spaced 21 days apart. A negative control group (N = 3) was not immunized. Splenocytes were collected 7 days after the second immunization (study day 28) and stimulated with a peptide pool (PP) that covers the entire spike protein for 6 h. b The number of IFN-γ secreting cells per million splenocytes was determined by ELISpot (n = 6/group). c, d The frequency of CD4⁺ memory T cells and CD8⁺ memory T cells producing IFN-γ, TNF-α, and IL-2, or at least 2 of 3 cytokines was determined by intracellular cytokine staining (n = 6/group). Analyzed cells were gated on the CD44^hiCD62L⁻ effector memory population. Bars represent the mean and the error bars indicate ±SD of triplicate assays. Individual animal values are indicated by colored symbols. Comparisons between groups receiving NVX-CoV2373 with and without adjuvant was performed by Student’s t-test (unpaired, two tail). e Pie charts represent the relative proportion of CD4⁺ and CD8⁺ T cells producing one, two, or three cytokines (IFN-γ, TNF-α, and IL-2) in mice immunized with NVX-CoV2373 antigen with and without Matrix-M. Source data are provided as a Source Data file.