Inclusion Criteria:  Confirmed SARS CoV-2 infection (PCR-test) Oxygen therapy (maximum 'high-flow' therapy) CRP plasma concentration ≥ 25 mg/l CRP increase ≥ 15mg/l within 48h after admission. Completed informed consent and written informed consent. Legal capacity  Exclusion Criteria:  Age < 18 years Pregnancy / lactation period Invasive, mechanical ventilation Extracorporeal membrane oxygenation (ECMO) support Participation in other interventional trials