PaO2 / FiO2 or respiratory rate (without oxygen);Frequency of respiratory exacerbation;Observe physical signs and symptoms and record clinical recovery time;The number and range of lesions indicated by CT and X-ray of lung;Time for cough to become mild or absent;Time for dyspnea to become mild or no dyspnea;Frequency of oxygen inhalation or noninvasive ventilation; frequency of mechanical ventilation;Inflammatory cytokines (CRP / PCT / SAA; etc.);Frequency of serious adverse events;

PaO2 / FiO2 or respiratory rate (without oxygen);Frequency of respiratory exacerbation;Observe physical signs and symptoms and record clinical recovery time;The number and range of lesions indicated by CT and X-ray of lung;Time for cough to become mild or absent;Time for dyspnea to become mild or no dyspnea;Frequency of oxygen inhalation or noninvasive ventilation; frequency of mechanical ventilation;Inflammatory cytokines (CRP / PCT / SAA; etc.);Frequency of serious adverse events;