Selective JAK2 inhibitors (eg, fedratinib) IL-23, IL-6 γδT17 cells, Th17, GM-CSF-producing T cells, mast cells, neutrophils Possibly inhibit inflammation in severe COVID-19 and do not interfere with JAK1-dependent interferon signalling Do not interfere with IL-9, IL-2, and IL-7-mediated expansion of effector T cells; might favour bacterial, viral, and opportunistic infections