CD4 and infection: Intra-group analysis based on infection status (N+ = infected; N− = uninfected) within the ChAd/ChAd and ChAd/BNT groups showed no significant differences in CD4+ T-cell cytokine expression (IFNγ, TNFα and CD154) between infected [N+] and uninfected [N−] individuals (Supplementary Figure S8A).