Fig. 2: Comparison of antigen-specific T cell responses induced in the airways following inhaled aerosol delivery of HuAd and ChAd vaccines in mRNA-vaccinated individuals without prior SARS-CoV-2 infection.

a BAL cells were stimulated with S1, NC or POL peptide pools. Three participants per dose/vaccine type. Scatter plots depict the fold-change (FC) in frequencies of IFN-γ + CD8 or CD4 T cells for each peptide pool at 4 weeks post-vaccination compared to baseline levels. b, Representative dotplots compare the frequencies (IFN-γ+ out of total CD8 T cells) of airway S1-, and NC -specific CD8 + IFN-γ + responses from participants vaccinated with 3 × 10⁷ TCID₅₀ HuAd or ChAd. The data are representative of three participants per vaccine type. c, d Scatter plots compare the frequencies of IFN-γ + CD8 or CD4 T cells specific for S1/NC, respectively. e Representative dotplots depict the multifunctional profile of S1-specific CD8 T cells. Pie charts compare mean frequencies of S1-specific CD8 T cells for 3+, 2+, and 1+ cytokines, identified by Boolean operator between HuAd and ChAd. The scatter plot compares the frequencies of multifunctional CD8 + T cells. f Representative dotplots show total CD8 T cells gated for CD103 and CD69 expression (gray dots), overlaid with IFN-γ + CD8 T cells specific for all three vaccine-encoded antigens (mega pool (MP)) (red dots) in airways of HuAd- or ChAd-vaccinated individuals. Pie charts compare mean frequencies of CD8 T cell expressing tissue resident markers using Boolean operator, between groups. Scatter plot show frequencies of antigen-specific resident memory and non-resident memory CD8 T cells. Each data point in all panels represents one participant. Three participants per dose/per vaccine type. All scatter plots show the median (horizontal line). Zero values were handled by adding a small constant (0.01) to all data points in all panels, expect for (e), where 0.001 added before transformation, as indicated by dotted lines in the scatter plots. The statistical differences between groups were determined using ordinary two-way ANOVA with Šidák multiple comparisons test on Log-transformed data for (a, c, d). Two-way ANOVA with Fisher’s LSD test on Log-transformed data was used to analyse statistical difference between groups for (e). Significant differences (p < 0.05) and p value < 0.1 are shown. Source data are provided as a Source Data file.