Figure 4. Cellular immune responses to SARS-CoV-2 in vaccinated 2-year convalescents detected by ICS.
A, Gating strategy for cytokines (IL-2, TNF-α, and IFN-γ) expressing in SARS-CoV-2-specific CD4+ and CD8+ T cells, enumerated by Intracellular cytokine staining (ICS). B, Representative dot plots showing IFN-γ production of CD4+ T cell against S1, S2, M, and N peptide pools in vaccinated 2-year convalescents (2Y-Vac) and vaccinated healthy controls (HC-Vac). C, The proportion of mean protein-specific responses of CD4+ and CD8+ T cells secreting IL-2, TNF-α, or IFN-γ from individuals in groups HC-Unvac (blue, n=5), HC-Vac (green, n=21), and 2Y-Vac (red, n=29). The solid lines represent the mean ± SEM. Statistical significance was performed with a Mann-Whitney U-test (C). * p < 0.05, ** p < 0.01, *** p < 0.001.