Following the administration of the second dose of mRNA-based COVID-19 vaccines, IFN-γ production in the uninfected group was significantly elevated compared with that after the first dose of vaccines, with a median of 1.76 (IQR 0.78–2.97) IU/mL, p < 0.001, whereas it declined slightly in the infected group [1.63 (IQR 1.09–3.69) IU/mL], p = 0.47, in response to AG1 stimulation (Fig. 2a and Table S1). The gene discussed is IFNG; the disease is COVID-19.