CD4 and COVID-19: We observed several folds of increases in the SARS-CoV-2 antigen-reactive T cells over the control T cells (Figure 5 and Supplementary Figure S2), indicating that DCs presenting the SMENP epitopes (CTL + COVID-19) elicited a strong anti-SARS-CoV-2 T-cell response in both CD4 and CD8 T cells (CD107a, IFN-γ, TNF-α, and IL-2, Figure 5B,C).