• Start of adjunctive ventilator support (HFNO, mechanical ventilation) or an indication to do so but due to due to previously agreed treatment restrictions HFNO or mechanical ventilation is not initiated. • Admission to an intensive care unit for progression of respiratory insufficiency. • No clinical improvement on day 7 after randomization or any day thereafter after first day of treatment (based on oxygen use in patients that require oxygen and based on clinical disease burden (including fever) in patients that require no oxygen). • Readmission for COVID-19.

• Start of adjunctive ventilator support (HFNO, mechanical ventilation) or an indication to do so but due to due to previously agreed treatment restrictions HFNO or mechanical ventilation is not initiated. • Admission to an intensive care unit for progression of respiratory insufficiency. • No clinical improvement on day 7 after randomization or any day thereafter after first day of treatment (based on oxygen use in patients that require oxygen and based on clinical disease burden (including fever) in patients that require no oxygen). • Readmission for COVID-19.