i. Require non-invasive ventilation, invasive mechanical ventilation, or extracorporeal membrane oxygenation (ECMO) on Day 1 at the time of randomization <br/ > ii. History of or known current thrombosis <br/ > iii. Have a personal or first-degree family history of blood clotting disorders. <br/ > iv. Participants who are immunocompromised, with known immunodeficiencies <br/ > v. Participants with any malignancy <br/ > vi. Severe hepatic impairment, defined as Child-Pugh class C. <br/ > vii. Severe anemia (hemoglobin <8 g/dL). <br/ > viii. Absolute lymphocyte count <500 cells/mm, <br/ > ix. Absolute neutrophil count <1000 cells/mm. <br/ > x. Known allergy to Tofacitinib. <br/ > xi. Other medical or psychiatric condition <br/ > xii. Suspected or known active systemic bacterial, fungal, or viral infections (with the exception of COVID-19) <br/ > xiii. Have received any of these within 4 weeks prior to the first dose of study intervention: any JAK inhibitors, potent immunosuppressants, or any biologic agents including IL-6 inhibitors (e.g., Tocilizumab) or IL-1 inhibitors (e.g., anakinra) within the past 30 days, any potent cytochrome P450 inducer, such as rifampin, within the past 28 days or 5 half-lives, whichever is longer. <br/ > xiv. Have received treatment with corticosteroids equivalent to prednisone or methylprednisolone >20 mg/day for equal or more than 14 consecutive days prior to screening. <br/ > xv. Current participation in other trials <br/ >

i. Require non-invasive ventilation, invasive mechanical ventilation, or extracorporeal membrane oxygenation (ECMO) on Day 1 at the time of randomization <br/ > ii. History of or known current thrombosis <br/ > iii. Have a personal or first-degree family history of blood clotting disorders. <br/ > iv. Participants who are immunocompromised, with known immunodeficiencies <br/ > v. Participants with any malignancy <br/ > vi. Severe hepatic impairment, defined as Child-Pugh class C. <br/ > vii. Severe anemia (hemoglobin <8 g/dL). <br/ > viii. Absolute lymphocyte count <500 cells/mm, <br/ > ix. Absolute neutrophil count <1000 cells/mm. <br/ > x. Known allergy to Tofacitinib. <br/ > xi. Other medical or psychiatric condition <br/ > xii. Suspected or known active systemic bacterial, fungal, or viral infections (with the exception of COVID-19) <br/ > xiii. Have received any of these within 4 weeks prior to the first dose of study intervention: any JAK inhibitors, potent immunosuppressants, or any biologic agents including IL-6 inhibitors (e.g., Tocilizumab) or IL-1 inhibitors (e.g., anakinra) within the past 30 days, any potent cytochrome P450 inducer, such as rifampin, within the past 28 days or 5 half-lives, whichever is longer. <br/ > xiv. Have received treatment with corticosteroids equivalent to prednisone or methylprednisolone >20 mg/day for equal or more than 14 consecutive days prior to screening. <br/ > xv. Current participation in other trials <br/ >