1. Pregnancy or breast feeding, 2. Refusal or inability to practice contraception regardless of the gender of the patient, 3. ALT and/or AST > 5 x ULN 4. Known, active auto-immune disease, 5. Ongoing cancer treatment with chemotherapy / immunotherapy or any cancer therapy within last 3 months and/or ongoing, 6. Patients with past history of Solid Organ transplant. 7. Active tuberculosis, uncontrolled active HBV or HCV infection, HIV with positive viral load. 8. Hospitalized patients with refractory hypoxia, defined as inability to maintain saturation >85% with maximal available therapy for >6 hours 9. Patients receiving any agent with immune suppressive effects, other than steroids at dosages less than 300mg/day and/or anti-IL6 treatments like Tocilizumab or Sarilumab which should preferably be minimized 10. Patients with baseline Rockwood Clinical Frailty Scale ≥ 6. 11. Patients under guardianship

1. Pregnancy or breast feeding, 2. Refusal or inability to practice contraception regardless of the gender of the patient, 3. ALT and/or AST > 5 x ULN 4. Known, active auto-immune disease, 5. Ongoing cancer treatment with chemotherapy / immunotherapy or any cancer therapy within last 3 months and/or ongoing, 6. Patients with past history of Solid Organ transplant. 7. Active tuberculosis, uncontrolled active HBV or HCV infection, HIV with positive viral load. 8. Hospitalized patients with refractory hypoxia, defined as inability to maintain saturation >85% with maximal available therapy for >6 hours 9. Patients receiving any agent with immune suppressive effects, other than steroids at dosages less than 300mg/day and/or anti-IL6 treatments like Tocilizumab or Sarilumab which should preferably be minimized 10. Patients with baseline Rockwood Clinical Frailty Scale ≥ 6. 11. Patients under guardianship