IFNG and COVID-19: By investigating if the SARS-CoV-2 specific cellular response could have a prognostic value, we found that a higher frequency of ER-measured specific T cells reduced the probability of developing severe COVID-19 (odds ratio [OR] per 100 IFN-γ sfu/106 PBMC increment: 0.45, 95%CI 0.20–0.76, p<0.05).