o be enrolled, all the following criteria must be met: 1) the confirmed patient (or legal guardian) agrees to participate in the study and signs the informed consent, 2) Aged 18-65 years, gender not limited, 3) the time interval between symptom onset and random enrollment was within 8 days (symptom onset was mainly determined by the time of fever), 4) real-time fluorescence rt-pcr detection of respiratory tract or blood samples in patients with positive nucleic acid of novel coronavirus, 5) diagnosis of mild, common or severe cases according to the diagnosis and treatment plan for pneumonia caused by novel coronavirus (trial version 5): A. Mild: the clinical symptoms were mild, and no pneumonia was found on imaging, B. Common type: symptoms such as fever and respiratory tract, and manifestations of pneumonia can be seen on imaging, C. Heavy: meets any of the following: A. respiratory distress, respiratory frequency >= 30 times/min, B. At rest, oxygen saturation (SaO2) <= 93%, C. Arterial partial oxygen pressure (PaO2)/oxygen absorption concentration (FiO2) <= 300mmHg.

o be enrolled, all the following criteria must be met: 1) the confirmed patient (or legal guardian) agrees to participate in the study and signs the informed consent, 2) Aged 18-65 years, gender not limited, 3) the time interval between symptom onset and random enrollment was within 8 days (symptom onset was mainly determined by the time of fever), 4) real-time fluorescence rt-pcr detection of respiratory tract or blood samples in patients with positive nucleic acid of novel coronavirus, 5) diagnosis of mild, common or severe cases according to the diagnosis and treatment plan for pneumonia caused by novel coronavirus (trial version 5): A. Mild: the clinical symptoms were mild, and no pneumonia was found on imaging, B. Common type: symptoms such as fever and respiratory tract, and manifestations of pneumonia can be seen on imaging, C. Heavy: meets any of the following: A. respiratory distress, respiratory frequency >= 30 times/min, B. At rest, oxygen saturation (SaO2) <= 93%, C. Arterial partial oxygen pressure (PaO2)/oxygen absorption concentration (FiO2) <= 300mmHg.