inclusion criteria: * subjects will be eligible for enrollment in the study only if they meet the following criteria: 1. male or female, aged between 25 years (including) to 90 years old 2. confirmed and documented covid-19 infection history with confirmed diagnosis of pulmonary fibrosis 3. negative to current covid-19 infection as tested by rt-pcr/rapid antigen tests 4. able to perform a 6-minute walk test 5. blood routine, liver and kidney functions test values are within controllable range 1. adequate hepatic function as evidenced by alt and ast \< 2x uln and bilirubin \< 1.5x uln for the reference lab 2. adequate renal function as evidenced by a serum creatinine ≤ 1.5 x uln for the reference laboratory or a calculated creatinine clearance of ≥ 60 ml/min by the cockcroft-gault equation 3. adequate hematopoietic function as evidenced by white blood cells ≥ 3x109 / l and platelets ≥ 100x109 / l 6. if childbearing age: agree to practice effective birth control from screening until 12 weeks after the last study treatment.

inclusion criteria: * subjects will be eligible for enrollment in the study only if they meet the following criteria: 1. male or female, aged between 25 years (including) to 90 years old 2. confirmed and documented covid-19 infection history with confirmed diagnosis of pulmonary fibrosis 3. negative to current covid-19 infection as tested by rt-pcr/rapid antigen tests 4. able to perform a 6-minute walk test 5. blood routine, liver and kidney functions test values are within controllable range 1. adequate hepatic function as evidenced by alt and ast \< 2x uln and bilirubin \< 1.5x uln for the reference lab 2. adequate renal function as evidenced by a serum creatinine ≤ 1.5 x uln for the reference laboratory or a calculated creatinine clearance of ≥ 60 ml/min by the cockcroft-gault equation 3. adequate hematopoietic function as evidenced by white blood cells ≥ 3x109 / l and platelets ≥ 100x109 / l 6. if childbearing age: agree to practice effective birth control from screening until 12 weeks after the last study treatment.

inclusion criteria: subjects will be eligible for enrollment in the study only if they meet the following criteria: male or female, aged between 25 years (including) to 90 years old confirmed and documented covid-19 infection history with confirmed diagnosis of pulmonary fibrosis negative to current covid-19 infection as tested by rt-pcr/rapid antigen tests able to perform a 6-minute walk test blood routine, liver and kidney functions test values are within controllable range adequate hepatic function as evidenced by alt and ast < 2x uln and bilirubin < 1.5x uln for the reference lab adequate renal function as evidenced by a serum creatinine ≤ 1.5 x uln for the reference laboratory or a calculated creatinine clearance of ≥ 60 ml/min by the cockcroft-gault equation adequate hematopoietic function as evidenced by white blood cells ≥ 3x109 / l and platelets ≥ 100x109 / l if childbearing age: agree to practice effective birth control from screening until 12 weeks after the last study treatment.

inclusion criteria: subjects will be eligible for enrollment in the study only if they meet the following criteria: male or female, aged between 25 years (including) to 90 years old confirmed and documented covid-19 infection history with confirmed diagnosis of pulmonary fibrosis negative to current covid-19 infection as tested by rt-pcr/rapid antigen tests able to perform a 6-minute walk test blood routine, liver and kidney functions test values are within controllable range adequate hepatic function as evidenced by alt and ast < 2x uln and bilirubin < 1.5x uln for the reference lab adequate renal function as evidenced by a serum creatinine ≤ 1.5 x uln for the reference laboratory or a calculated creatinine clearance of ≥ 60 ml/min by the cockcroft-gault equation adequate hematopoietic function as evidenced by white blood cells ≥ 3x109 / l and platelets ≥ 100x109 / l if childbearing age: agree to practice effective birth control from screening until 12 weeks after the last study treatment.

inclusion criteria: subjects will be eligible for enrollment in the study only if they meet the following criteria: male or female, aged between 25 years (including) to 90 years old confirmed and documented covid-19 infection history with confirmed diagnosis of pulmonary fibrosis negative to current covid-19 infection as tested by rt-pcr tests able to perform a 6-minute walk test blood routine, liver and kidney functions test values are within controllable range adequate hepatic function as evidenced by alt, ast and ldh < 2x uln and bilirubin < 1.5x uln for the reference lab adequate renal function as evidenced by a serum creatinine ≤ 1.5 x uln for the reference laboratory or a calculated creatinine clearance of ≥ 60 ml/min by the cockcroft-gault equation adequate hematopoietic function as evidenced by white blood cells ≥ 3x109 / l and platelets ≥ 100x109 / l if childbearing age: agree to practice effective birth control from screening until 12 weeks after the last study treatment.

inclusion criteria: subjects will be eligible for enrollment in the study only if they meet the following criteria: male or female, aged between 25 years (including) to 90 years old confirmed and documented covid-19 infection history with confirmed diagnosis of pulmonary fibrosis negative to current covid-19 infection as tested by rt-pcr tests able to perform a 6-minute walk test blood routine, liver and kidney functions test values are within controllable range adequate hepatic function as evidenced by alt, ast and ldh < 2x uln and bilirubin < 1.5x uln for the reference lab adequate renal function as evidenced by a serum creatinine ≤ 1.5 x uln for the reference laboratory or a calculated creatinine clearance of ≥ 60 ml/min by the cockcroft-gault equation adequate hematopoietic function as evidenced by white blood cells ≥ 3x109 / l and platelets ≥ 100x109 / l if childbearing age: agree to practice effective birth control from screening until 12 weeks after the last study treatment.

None

None

inclusion criteria: subjects will be eligible for enrollment in the study only if they meet the following criteria: male or female, aged between 25 years (including) to 90 years old confirmed and documented covid-19 infection history with confirmed diagnosis of pulmonary fibrosis negative to current covid-19 infection as tested by rt-pcr tests able to perform a 6-minute walk test blood routine, liver and kidney functions test values are within controllable range adequate hepatic function as evidenced by alt, ast and ldh < 2x uln and bilirubin < 1.5x uln for the reference lab adequate renal function as evidenced by a serum creatinine ≤ 1.5 x uln for the reference laboratory or a calculated creatinine clearance of ≥ 60 ml/min by the cockcroft-gault equation adequate hematopoietic function as evidenced by white blood cells ≥ 3x109 / l and platelets ≥ 100x109 / l if childbearing age: agree to practice effective birth control from screening until 12 weeks after the last study treatment.

inclusion criteria: subjects will be eligible for enrollment in the study only if they meet the following criteria: male or female, aged between 25 years (including) to 90 years old confirmed and documented covid-19 infection history with confirmed diagnosis of pulmonary fibrosis negative to current covid-19 infection as tested by rt-pcr tests able to perform a 6-minute walk test blood routine, liver and kidney functions test values are within controllable range adequate hepatic function as evidenced by alt, ast and ldh < 2x uln and bilirubin < 1.5x uln for the reference lab adequate renal function as evidenced by a serum creatinine ≤ 1.5 x uln for the reference laboratory or a calculated creatinine clearance of ≥ 60 ml/min by the cockcroft-gault equation adequate hematopoietic function as evidenced by white blood cells ≥ 3x109 / l and platelets ≥ 100x109 / l if childbearing age: agree to practice effective birth control from screening until 12 weeks after the last study treatment.