Efficacy of Bailing Capsule on Pulmonary Fibrosis After COVID-19

Inclusion Criteria: 1. Age 18-80 years old, gender unlimited; 2. Fibrous changes in the lungs after COVID-19 pneumonia: 1. If COVID-19 is positive within the past 2 months, qualitative analysis of SARS-CoV-2 RNA is conducted by antigen detection or PCR detection; 2. During the screening period, chest HRCT showed the characteristics of pulmonary interstitial lesions (including ground glass shadow, grid shadow, tractable bronchiectasis, septal thickening and early honeycomb shadow, etc.), with fibrosis affected area \> 5%; 3. COVID-19 negative was confirmed during the screening period, and SARS-CoV-2 RNA was qualitatively verified by antigen detection or PCR detection; 3. Severity grade 2 (moderate) or 3 (severe) according to the mMRC Dyspnea Scale at the screening visit; 4. Able to perform pulmonary function tests (PFT) and decreased lung function FVC and/or DLCO \<70% of the predicted value at the screening visit; 5. Able to complete the 6-minute walking test and questionnaire survey; 6. Fertile female patients must have negative pregnancy test results during screening; 7. Volunteer to participate in this clinical trial and sign an informed consent form. Exclusion Criteria: 1. Prior medical history of lung disease (including IPF, bronchial asthma, COPD, lung cancer or pulmonary hypertension) prior to positive diagnosis of COVID-19 pneumonia; 2. Nephrotic syndrome, moderate to severe chronic renal failure, or eGFR \< 60ml/min at enrollment; 3. Major cardiovascular disease, including chronic heart failure grade III or IV, clinically significant sinus arrhythmias, ventricular tachycardia, ventricular fibrillation, unstable angina, and severe hypertension (≥160/110 mmHg) that was not under control or was being actively treated within the first 6 months of enrollment; 4. Screening of patients with abnormal liver function, the criteria are as follows: total bilirubin \> 1.5×ULN; ALT \> 3 x ULN; AST \> 3 x ULN; 5. Severe pulmonary arterial hypertension (PAH) meets any of the following conditions: 1. severe right heart failure in the past; 2. Cardiac index indicated by right cardiac catheter insertion history ≤2 L/min/m²; 3. PAH requiring epizoprostol/treprostol parenteral treatment; 6. Patients with bleeding risk: 1. Known genetic susceptibility to bleeding; 2. fibrinolysis, full-dose anticoagulant therapy, or high-dose antiplatelet therapy are required; 7. Patients had received chest and neck radiotherapy or chemotherapy before screening; 8. Inability to swallow the study drug; 9. History of active malabsorption disorders or gastrointestinal resection; 10. Systemic corticosteroids (e.g. Prednisone, dexamethasone) were administered within 5 days of the first day of administration of the study intervention; 11. After discharge, take preparations containing cordyceps or anti-pulmonary fibrosis drugs (such as pirfenidone, Nidanib, imatinib, penicillamine, colchicine, tumor necrosis factor α receptor blockers, etc.); 12. Participation in other clinical trials, use of other investigational drugs or investigational devices within 30 days prior to randomization; 13. Women or men of childbearing age refuse to use contraception during the study period; 14. Pregnant or lactating women; 15. Any other factors that the investigator has determined may be inappropriate for participation in the clinical study; 16. Patients suffered major trauma or underwent major surgery within 28 days prior to treatment with the study drug; 17. Other Chinese medicines containing cordyceps were used for treatment within 15 days before and during the study period.