- Positive COVID status as defined by: PCR documented SARS-CoV-2 carriage in nasopharyngeal sample or evocative thoracic scan images of COVID-19 associated with typical clinical presentation - Hospitalized patients aged ≥ 18 and ≤ 75 years old - Signs of severe COVID-19 pneumonia (3 of the followings) - Patient wheezing or unable to speak in full sentences while at rest/with minimal effort - Respiratory rate >22 - PaO2 <65 mmHg or SpO2 <90% - Repeated chest imaging is significantly worsening despite being on standard of care, which may include anti-viral treatment, low dose steroids and antibiotics.

- Positive COVID status as defined by: PCR documented SARS-CoV-2 carriage in nasopharyngeal sample or evocative thoracic scan images of COVID-19 associated with typical clinical presentation - Hospitalized patients aged ≥ 18 and ≤ 75 years old - Signs of severe COVID-19 pneumonia (3 of the followings) - Patient wheezing or unable to speak in full sentences while at rest/with minimal effort - Respiratory rate >22 - PaO2 <65 mmHg or SpO2 <90% - Repeated chest imaging is significantly worsening despite being on standard of care, which may include anti-viral treatment, low dose steroids and antibiotics.