Inclusion Criteria:

- Age ≥ 65;

- Male or female;

- Positive test for coronavirus antigen or nucleic acid；

- Within 7 days of onset (fever and/or cough) ；

- mild and moderate；Mild: respiratory tract infection is the main manifestation, such
as dry throat, sore throat, cough, fever；Moderate: continuous high fever>3 days or
(and) cough, shortness of breath, etc., but respiratory rate (RR)<30 times/minute,
oxygen saturation>93% when breathing air at rest. Imaging findings of characteristic
pneumonia caused by COVID-19 infection；

- The patient is willing to participate in the trial treatment and follow-up, and sign
the informed consent form (if the patient lacks the ability to give informed consent
due to his serious medical condition, such as acute respiratory failure or the need
for respiratory support, he can obtain the consent of the patient's legal
representative)；

- No systemic glucocorticoids treatment in the past 7 days；

Exclusion Criteria:

- Serious and uncontrolled comorbidities；

- Expected lifetime is less than 1 month；

- Severe/critical;

- Other situations that are evaluated by researchers as not suitable for participating
the study.

Criteria for discontinuation

- The subject could not benefit after treatment (discontinued patients could be
analyzed according to the PP analysis set);

Withdrawal criteria (if any of the following items are required)

- The subject asked to withdraw from the study;

- The subject needs to withdraw from the study after clinical observation after
discontinuing treatment;

- The subject died or lost to follow-up.