IFNG and COVID-19: Currently, two types of IGRA tests are available for evaluation of the IFN‐γ released by T‐cells following the COVID‐19 vaccination or SARS‐CoV‐2 infection: Quanti‐FERON (QFN) SARS‐CoV‐2 (QIAGEN) and T SPOT Discovery SARS‐CoV‐2 kit (Oxford Immunotec).