Cumulative Incidence (Percentage of Participants) With Successful Tracheal Extubation at Day 14 -- Critical COVID Population (WHO Clinical Progression Scale >5 at Baseline);Percentage of Participants With no Improvement in WHO Clinical Progression Scale at Day 4 -- Critical COVID Population ( WHO Clinical Progression Scale >5 at Baseline);Percentage of Participants With Non-invasive Ventilation, Mechanical Ventilation or Death at Day 14 (WHO Clinical Progression Scale =5 at Baseline);Percentage of Participants With WHO Clinical Progression Scale > 5 at Day 4 -- Severe COVID Population (WHO Clinical Progression Scale =5 at Baseline)

Cumulative Incidence (Percentage of Participants) With Successful Tracheal Extubation at Day 14 -- Critical COVID Population (WHO Clinical Progression Scale >5 at Baseline);Percentage of Participants With no Improvement in WHO Clinical Progression Scale at Day 4 -- Critical COVID Population ( WHO Clinical Progression Scale >5 at Baseline);Percentage of Participants With Non-invasive Ventilation, Mechanical Ventilation or Death at Day 14 (WHO Clinical Progression Scale =5 at Baseline);Percentage of Participants With WHO Clinical Progression Scale > 5 at Day 4 -- Severe COVID Population (WHO Clinical Progression Scale =5 at Baseline)

Survival without needs of ventilator utilization at day 14.;WHO progression scale <=5 at day 4;Cumulative incidence of successful tracheal extubation (defined as duration extubation > 48h) at day 14;WHO progression scale at day 4

Survival without needs of ventilator utilization at day 14.;WHO progression scale <=5 at day 4;Cumulative incidence of successful tracheal extubation (defined as duration extubation > 48h) at day 14;WHO progression scale at day 4