IFNG and cancer: Whilst the vaccination‐induced T‐cell response in cancer patients recovered to similar levels observed for healthy donors following the second dose (Figure 3E,F), a significant reduction in the overall proportion of cancer patients mounting IFN‐γ+ (p = 0·034) but not IL‐2+ (p = 0·29) SARS‐CoV‐2‐specific T‐cell responses remained (Table 2).