- Inclusion in another interventional clinical trial - Age < 18 - Age > 80 - Patients who are pregnant or lactating - Patients expected to have fatal disease within 24 hours - Patients who are already on dialysis (Renal Replacement Therapy, RRT) or a decision has been made to initiate RRT within 24 hours after planned start of study drug administration - Patients who have advanced chronic liver disease confirmed by a Child-Pugh C - Patients who are having an known history of immune system that has been impaired by disease, such as patients with HIV and with a CD4 count of less than 200 cells/mm, neutropenic patients (<0.5 x 109/l) or patients who are receiving chronic high doses (equivalent to prednisone/prednisolone 0.5 mg/kg/day) steroids therapy immediately prior to recruitment exceeding 2 weeks of treatment. This means dexamethasone 6 mg once daily serving as treatment for severe COVID-19 is not an exclusion criteria. - Patients with active haematological malignancy

- Inclusion in another interventional clinical trial - Age < 18 - Age > 80 - Patients who are pregnant or lactating - Patients expected to have fatal disease within 24 hours - Patients who are already on dialysis (Renal Replacement Therapy, RRT) or a decision has been made to initiate RRT within 24 hours after planned start of study drug administration - Patients who have advanced chronic liver disease confirmed by a Child-Pugh C - Patients who are having an known history of immune system that has been impaired by disease, such as patients with HIV and with a CD4 count of less than 200 cells/mm, neutropenic patients (<0.5 x 109/l) or patients who are receiving chronic high doses (equivalent to prednisone/prednisolone 0.5 mg/kg/day) steroids therapy immediately prior to recruitment exceeding 2 weeks of treatment. This means dexamethasone 6 mg once daily serving as treatment for severe COVID-19 is not an exclusion criteria. - Patients with active haematological malignancy