Additionally, the differentiating power of copeptin between the COVID-19 patients' severity was nearly similar to the finding of Gregorianoet al., where their optimal cut-off value was 20 Pmol/l with a sensitivity 88.2% and specificity 64.9% [13], while our optimal cut-off value was 18.5 Pmol/l with sensitivity 93.33% and specificity 100%. This evidence concerns the gene AVP and COVID-19.