Fig. 5

Mutations in the spike proteins of B.1.1.7 and B.1.351 slightly interfere with the T-cell responses to SARS-CoV-2. The frequencies of spike-specific IFN-γ⁺CD4⁺ T cells (A) and IFN-γ⁺CD8⁺ T cells (B) elicited by 19 groups of DNA immunogens after stimulation with the full wild-type spike peptide pool (Wuhan Hu-1). Data were analyzed for statistical significance using an unpaired Student’s t test. Data are shown as the mean with SD in each group. The percentage of antigen-specific IFN-γ⁺CD4⁺ T cells (C) and IFN-γ⁺ CD8⁺ T cells (D) induced by the D614G, B.1.1.7 and B.1.351 lineages to different ex vivo antigen peptide mixture stimulations, including the full wild-type spike peptide pool (WT), wild-type amino acid-containing peptide pool, mutation-containing peptide pool, B.1.1.7 pool (Alpha) and B.1.351 pool (Beta) (detailed peptide pool information is provided in Supplementary Table 4). The numbers above each bar indicate the numbers of positive responders. Dotted black lines indicate the limit of quantification (LOQ) in (A–D)