**EU SOLIDACT PLATFORM INCLUSION CRITERIA**:  Participants are eligible to be included in the study only if all the following general inclusion (GI) criteria apply:  GI1. ≥ 18 years of age GI2. Laboratory-confirmed SARS-CoV-2 infection (new infection or reinfection) as determined by PCR not more than 14 days old. GI3. Admitted to hospital GI4. Informed consent by the participant or legally authorized representative GI5A (SolidAct part A): Moderate disease state defined as hospitalised patients without oxygen therapy or oxygen by mask or nasal prongs needed, or  GI5B (SolidAct part B): Severe/critical disease state defined as fulfilling at least one of the following criteria:  SpO2<90% on room air, or SpO2 90-94% with a downwards trend and/or signs of respiratory distress*, or Need of oxygen by NIV (CPAP, BIPAP), high flow or non-rebreather mask, or  Need of mechanical ventilation/ECMO  *persistently increased respiratory rate, use of accessory muscles, inability to complete full sentences. Clinical judgement must be applied to determine whether a low oxygen saturation is indicative of disease progression or severity or is habitual for a given patient (i.e., with underlying chronic lung disease).  NIV=non-invasive ventilation. CPAP= Continuous Positive Airway Pressure, BPAP= Bi-level Positive Airway Pressure, ECMO = extracorporeal membrane oxygenation.  Additional inclusion criteria are given in the intervention-specific sub-protocols.  **EU SOLIDACT PLATFORM EXCLUSION CRITERIA**:  Participants are excluded from the study if any of the following general exclusion criteria (GE) apply:  GE1. Anticipated transfer to another non-trial hospital within 72 hours Additional exclusion criteria, including prohibited medication, confounding trials and details on contraception and pregnancy are given in the intervention-specific sub-protocols