Figure 6. T cell cross-response to Omicron in vaccinated 2-year convalescents and healthy controls.
A, Representative ELISpot responses against RBD, S1, and S2 protein pools of wild type (WT) and Omicron BA.1. B, Comparative T cell responses in vaccinated 2-year convalescents (2Y-Vac, red, n=51) and healthy controls without COVID-19 infection (HC-Vac, blue, n=35) to peptide pools of WT and BA.1 RBD/S1/S2. C-D, Frequency of spike-reactive CD4+ and CD8+ T cells producing IL-2, TNF-α, or IFN-γ cytokines after PBMCs of vaccinated 2-year convalescents (C) and healthy controls (D) stimulated with S1 (C, n=5; D, n=7) and S2 (C, n=4; D, n=3) peptide pools from WT (red) and Omicron BA.1 (blue). Each dot represents an individual. A Mann-Whitney U-test was used to calculate statistical significance (B). * p < 0.05, ** p < 0.01, *** p < 0.001.