1. Male or female, 18-95 years old, 2. 2019 new coronavirus nucleic acid test positive, 3. Diagnosed as moderate to severe cases of new coronavirus pneumonia in 2019, which meets the following clinical manifestations: 4. With fever and respiratory symptoms, imaging shows pneumonia, 5. A severe case diagnosed with 2019 new coronavirus pneumonia, that is, any of the following: (1) Increased breathing rate (>=30 beats / min), difficulty breathing, cyanosis of lips, (2) In the resting state, it means that oxygen saturation <=93%, or blood oxygen drops rapidly, (3) Arterial blood oxygen partial pressure (PaO2) / oxygen concentration (FiO2) <=300mmHg (1mmHg = 0.133kPa), 6. I or the authorized agent signed the informed consent form, 7. Agree to collect clinical samples.

1. Male or female, 18-95 years old, 2. 2019 new coronavirus nucleic acid test positive, 3. Diagnosed as moderate to severe cases of new coronavirus pneumonia in 2019, which meets the following clinical manifestations: 4. With fever and respiratory symptoms, imaging shows pneumonia, 5. A severe case diagnosed with 2019 new coronavirus pneumonia, that is, any of the following: (1) Increased breathing rate (>=30 beats / min), difficulty breathing, cyanosis of lips, (2) In the resting state, it means that oxygen saturation <=93%, or blood oxygen drops rapidly, (3) Arterial blood oxygen partial pressure (PaO2) / oxygen concentration (FiO2) <=300mmHg (1mmHg = 0.133kPa), 6. I or the authorized agent signed the informed consent form, 7. Agree to collect clinical samples.