Given that CD57 is a marker of replicative senescence27 and replicative senescence results in a low proliferative capacity of cells and inability to eradicate infection28,29, our observations make us question if down regulation of senescence affecting both NK and T cell compartments (in our patients) during severe COVID-19 leads to efficient clearance of SARS-CoV-2 virus. This evidence concerns the gene B3GAT1 and COVID-19.