Extended Data Fig. 8: BBV152 vaccination induces SARS-CoV-2 specific CD8+ T cells.
SARS-CoV-2-specific CD8+ T cells were quantified in PBMCs derived from the individuals vaccinated with BBV152 (‘BBV152’) and individuals recovered from mild COVID-19 (‘COVID-19’). The SARS-CoV-2-specific CD8+ T cells were quantified in AIM assay as a percentage population of AIM+ (CD69+CD137+) CD8+ T cells, after stimulation of PBMCs with overlapping peptide megapools (MP) spanning spike glycoprotein of ancestral SARS-CoV-2, nucleoprotein of SARS-CoV-2 or the MP specific to the spike protein of VOCs. Equimolar DMSO was used as the negative control and CMV MP was used as the positive stimulation control. Representative gating strategy for measuring the antigen-specific AIM+ (CD69+CD137+) CD8+ T cells in the total CD8+ T cells from (a) BBV152 and (b) COVID-19 (see Extended data Fig. 4 for detailed gating strategy). The numbers on the lower right corners of the contour plots represent the frequency of AIM+ cells in the total CD8+ T cells. (c) Frequency of total CD8+ T cells in BBV152 and COVID-19, (d) Comparison of background subtracted spike-specific CD8+ T cells in BBV152 and COVID-19 groups, (e) Comparison of background subtracted nucleoprotein-specific CD8+ T cells in BBV152 and COVID-19, (f) CMV-specific CD8+ T cells in BBV152 versus COVID-19. Quantitation of spike-specific CD8+ T cells responding to ancestral SARS-CoV-2 and VOCs – Alpha (B.1.1.7), Beta (B.1.351) and Delta (B.1.617.2) in individuals after (g) vaccination and (h) recovery from COVID-19. Values in parentheses represents fold-reduction in spike-specific CD8+ T cells responding to VOCs over ancestral virus. Black bars indicate median. Dotted line represents the limit of positivity. Statistics by (c-f) two-tail Mann-Whitney test, (g-h) two-tail Wilcoxon signed-rank test. ns: non-significant.
