inclusion criteria: 1. the age of the subjects when signing the icf is 18 to 70 years old (including 18 and 70 years old), male or female; 2. possess venous access conditions, allowing drug administration and blood sample collection according to the research protocol; 3. sars-cov-2 positive in any laboratory-confirmed sample within 96 hours before screening; 4. according to the national health commission of the people's republic of china (nhc) "new coronary virus pneumonia diagnosis and treatment program", the ninth revised version of the trial was clinically classified as mild/ordinary patients; 5. there is at least one factor that may lead to a high risk of severe/critical covid-19: ① age \> 60 years; ② cardiovascular and cerebrovascular diseases (including hypertension), chronic lung diseases (chronic obstructive pulmonary disease, chronic obstructive pulmonary disease, moderate to severe asthma), diabetes, chronic liver, kidney disease, tumor and other basic diseases; ③ immunodeficiency (such as aids patients, long-term use of corticosteroids or other immunosuppressive drugs lead to immunosuppression); ④ obesity (physical constitution) index ≥ 30); ⑤ heavy smokers. 6. symptoms of covid-19 ≤ 5 days before randomization; such as fever, cough, shortness of breath, sore throat, diarrhea, vomiting, and dysgeusia; 7. agree to collect nasopharyngeal swabs, saliva and venous blood; 8. the subjects can communicate well with the researcher, understand and comply with the requirements of this study, and understand and sign the icf.

inclusion criteria: 1. the age of the subjects when signing the icf is 18 to 70 years old (including 18 and 70 years old), male or female; 2. possess venous access conditions, allowing drug administration and blood sample collection according to the research protocol; 3. sars-cov-2 positive in any laboratory-confirmed sample within 96 hours before screening; 4. according to the national health commission of the people's republic of china (nhc) "new coronary virus pneumonia diagnosis and treatment program", the ninth revised version of the trial was clinically classified as mild/ordinary patients; 5. there is at least one factor that may lead to a high risk of severe/critical covid-19: ① age \> 60 years; ② cardiovascular and cerebrovascular diseases (including hypertension), chronic lung diseases (chronic obstructive pulmonary disease, chronic obstructive pulmonary disease, moderate to severe asthma), diabetes, chronic liver, kidney disease, tumor and other basic diseases; ③ immunodeficiency (such as aids patients, long-term use of corticosteroids or other immunosuppressive drugs lead to immunosuppression); ④ obesity (physical constitution) index ≥ 30); ⑤ heavy smokers. 6. symptoms of covid-19 ≤ 5 days before randomization; such as fever, cough, shortness of breath, sore throat, diarrhea, vomiting, and dysgeusia; 7. agree to collect nasopharyngeal swabs, saliva and venous blood; 8. the subjects can communicate well with the researcher, understand and comply with the requirements of this study, and understand and sign the icf.

inclusion criteria: the age of the subjects when signing the icf is 18 to 70 years old (including 18 and 70 years old), male or female; possess venous access conditions, allowing drug administration and blood sample collection according to the research protocol; sars-cov-2 positive in any laboratory-confirmed sample within 96 hours before screening; according to the national health commission of the people's republic of china (nhc) "new coronary virus pneumonia diagnosis and treatment program", the ninth revised version of the trial was clinically classified as mild/ordinary patients; there is at least one factor that may lead to a high risk of severe/critical covid-19: ① age > 60 years; ② cardiovascular and cerebrovascular diseases (including hypertension), chronic lung diseases (chronic obstructive pulmonary disease, chronic obstructive pulmonary disease, moderate to severe asthma), diabetes, chronic liver, kidney disease, tumor and other basic diseases; ③ immunodeficiency (such as aids patients, long-term use of corticosteroids or other immunosuppressive drugs lead to immunosuppression); ④ obesity (physical constitution) index ≥ 30); ⑤ heavy smokers. symptoms of covid-19 ≤ 5 days before randomization; such as fever, cough, shortness of breath, sore throat, diarrhea, vomiting, and dysgeusia; agree to collect nasopharyngeal swabs, saliva and venous blood; the subjects can communicate well with the researcher, understand and comply with the requirements of this study, and understand and sign the icf.

inclusion criteria: the age of the subjects when signing the icf is 18 to 70 years old (including 18 and 70 years old), male or female; possess venous access conditions, allowing drug administration and blood sample collection according to the research protocol; sars-cov-2 positive in any laboratory-confirmed sample within 96 hours before screening; according to the national health commission of the people's republic of china (nhc) "new coronary virus pneumonia diagnosis and treatment program", the ninth revised version of the trial was clinically classified as mild/ordinary patients; there is at least one factor that may lead to a high risk of severe/critical covid-19: ① age > 60 years; ② cardiovascular and cerebrovascular diseases (including hypertension), chronic lung diseases (chronic obstructive pulmonary disease, chronic obstructive pulmonary disease, moderate to severe asthma), diabetes, chronic liver, kidney disease, tumor and other basic diseases; ③ immunodeficiency (such as aids patients, long-term use of corticosteroids or other immunosuppressive drugs lead to immunosuppression); ④ obesity (physical constitution) index ≥ 30); ⑤ heavy smokers. symptoms of covid-19 ≤ 5 days before randomization; such as fever, cough, shortness of breath, sore throat, diarrhea, vomiting, and dysgeusia; agree to collect nasopharyngeal swabs, saliva and venous blood; the subjects can communicate well with the researcher, understand and comply with the requirements of this study, and understand and sign the icf.