The level of IFN-γ in PLWH was 9.8 (IQR: 8.4, 14.7) pg/mL, which was lower than that in HCs (46.4 pg/mL, IQR: 12.7, 94.1) at 28 days after the second dose of inactivated COVID-19 vaccine. Here, IFNG is linked to COVID-19.