1. where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; 2. refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; 3. severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; 4. gout/history of gout or hyperuricemia (above the uln); 5. oxygen saturation (spo2) ≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2) ≤300 mmhg; 6. known allergy or hypersensitivity to favipiravir or any of its excipients, or to placebo excipients 7. known severe renal impairment \[creatinine clearance (crcl) \<30 ml/min\] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; 8. possibility of the subject being transferred to a non-study hospital within 72h; 9. pregnant or lactating women; 10. having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug or having received treatments with other investigational medicinal products (imps) or previous therapies within two weeks or five times the half-life of the drug, whichever is longer, must lead to exclusion 11. persons, who were placed in an institution due to official or legal orders should be excluded 12. persons, who are dependent on the sponsor, the investigator or the trial site, meaning that the voluntary nature of their consent is no longer guaranteed, must be excluded from participation

1. where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; 2. refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; 3. severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; 4. gout/history of gout or hyperuricemia (above the uln); 5. oxygen saturation (spo2) ≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2) ≤300 mmhg; 6. known allergy or hypersensitivity to favipiravir or any of its excipients, or to placebo excipients 7. known severe renal impairment \[creatinine clearance (crcl) \<30 ml/min\] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; 8. possibility of the subject being transferred to a non-study hospital within 72h; 9. pregnant or lactating women; 10. having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug or having received treatments with other investigational medicinal products (imps) or previous therapies within two weeks or five times the half-life of the drug, whichever is longer, must lead to exclusion 11. persons, who were placed in an institution due to official or legal orders should be excluded 12. persons, who are dependent on the sponsor, the investigator or the trial site, meaning that the voluntary nature of their consent is no longer guaranteed, must be excluded from participation

where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; gout/history of gout or hyperuricemia (above the uln); oxygen saturation (spo2) ≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2) ≤300 mmhg; known allergy or hypersensitivity to favipiravir or any of its excipients, or to placebo excipients known severe renal impairment [creatinine clearance (crcl) <30 ml/min] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; possibility of the subject being transferred to a non-study hospital within 72h; pregnant or lactating women; having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug or having received treatments with other investigational medicinal products (imps) or previous therapies within two weeks or five times the half-life of the drug, whichever is longer, must lead to exclusion persons, who were placed in an institution due to official or legal orders should be excluded persons, who are dependent on the sponsor, the investigator or the trial site, meaning that the voluntary nature of their consent is no longer guaranteed, must be excluded from participation

where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; gout/history of gout or hyperuricemia (above the uln); oxygen saturation (spo2) ≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2) ≤300 mmhg; known allergy or hypersensitivity to favipiravir or any of its excipients, or to placebo excipients known severe renal impairment [creatinine clearance (crcl) <30 ml/min] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; possibility of the subject being transferred to a non-study hospital within 72h; pregnant or lactating women; having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug or having received treatments with other investigational medicinal products (imps) or previous therapies within two weeks or five times the half-life of the drug, whichever is longer, must lead to exclusion persons, who were placed in an institution due to official or legal orders should be excluded persons, who are dependent on the sponsor, the investigator or the trial site, meaning that the voluntary nature of their consent is no longer guaranteed, must be excluded from participation

1. where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; 2. refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; 3. severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; 4. gout/history of gout or hyperuricemia (above the uln); 5. oxygen saturation (spo2) ≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2) ≤300 mmhg; 6. known allergy or hypersensitivity to favipiravir or any of its excipients, or to placebo excipients 7. known severe renal impairment [creatinine clearance (crcl) <30 ml/min] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; 8. possibility of the subject being transferred to a non-study hospital within 72h; 9. pregnant or lactating women; 10. having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug or having received treatments with other investigational medicinal products (imps) or previous therapies within two weeks or five times the half-life of the drug, whichever is longer, must lead to exclusion 11. persons, who were placed in an institution due to official or legal orders should be excluded 12. persons, who are dependent on the sponsor, the investigator or the trial site, meaning that the voluntary nature of their consent is no longer guaranteed, must be excluded from participation

1. where, in the opinion of the investigator, participation in this study will not be in the best interest of the subject, or any other circumstances that prevent the subject from participating in the study safely; 2. refractory nausea, vomiting, or chronic gastrointestinal disorders, inability to swallow the study drug or having undergone extensive bowel resection which may affect adequate absorption of favipiravir; 3. severe liver disease: underlying liver cirrhosis or alanine aminotransferase (alt)/aspartate aminotransferase (ast) elevated over 5 times the uln; 4. gout/history of gout or hyperuricemia (above the uln); 5. oxygen saturation (spo2) ≤93% or arterial oxygen partial pressure (pao2)/ fraction of inspired o2 (fio2) ≤300 mmhg; 6. known allergy or hypersensitivity to favipiravir or any of its excipients, or to placebo excipients 7. known severe renal impairment [creatinine clearance (crcl) <30 ml/min] or having received continuous renal replacement therapy, hemodialysis or peritoneal dialysis; 8. possibility of the subject being transferred to a non-study hospital within 72h; 9. pregnant or lactating women; 10. having used favipiravir or participated in any other interventional drug clinical study within 30 days prior to first dose of study drug or having received treatments with other investigational medicinal products (imps) or previous therapies within two weeks or five times the half-life of the drug, whichever is longer, must lead to exclusion 11. persons, who were placed in an institution due to official or legal orders should be excluded 12. persons, who are dependent on the sponsor, the investigator or the trial site, meaning that the voluntary nature of their consent is no longer guaranteed, must be excluded from participation