* travel history / residence history of communities with case reports within 14 days; * history of contact with a sars-cov-2 infection (positive in nucleic acid test) within 14 days; * have contacted patients with fever or respiratory symptoms from communities with case reports within 14 days; * two or more cases of fever and / or respiratory symptoms in a small contact area of volunteers, such as home, office etc. within 14 days; * history of sars-cov-2 infection; * history of asthma, history of allergy to the vaccine or vaccine components, or serious adverse reactions to the vaccine, such as urticaria, dyspnea, and angioedema; * congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc.; * autoimmune disease or immunodeficiency / immunosuppression; * severe chronic diseases, severe cardiovascular diseases, hypertension and diabetes that cannot be controlled by drugs, liver or kidney diseases, malignant tumors, etc.; * severe neurological disease (epilepsy, convulsions or convulsions) or mental illness; * thyroid disease or history of thyroidectomy, spleenlessness, functional spleenlessness, spleenlessness or splenectomy resulting from any condition; * diagnosed abnormal blood coagulation function (eg, lack of blood coagulation factors, blood coagulopathy, abnormal platelets) or obvious bruising or blood coagulation; * immunosuppressive therapy, cytotoxic therapy, inhaled corticosteroids (excluding allergic rhinitis corticosteroid spray therapy, acute noncomplicated dermatitis superficial corticosteroid therapy) in the past 6 months; * physical examination has clinically significant abnormal hematology and biochemistry laboratory test results that exceed the reference value range (only applicable to phase i clinical trials): 1. blood routine test: white blood cell count, hemoglobin, platelet count; 2. detection of blood biochemical indicators: alanine aminotransferase (alt), aspartate aminotransferase (ast), total bilirubin (tbil), creatinine (cr), fasting blood glucose; 3. urine routine index: urine protein (pro); * history of alcohol or drug abuse; * receipt of blood products within in the past 3 months; * receipt of other investigational drugs in the past 30 days; * receipt of attenuated live vaccines in the past 14 days; * receipt of inactivated or subunit vaccines in the past 7 days; * acute diseases or acute exacerbation of chronic diseases in the past 7 days; * axillary temperature \>37.0°c; * already pregnant (including a positive urine pregnancy test) or are breastfeeding, planning to get pregnant within 3 months; * according to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.

* travel history / residence history of communities with case reports within 14 days; * history of contact with a sars-cov-2 infection (positive in nucleic acid test) within 14 days; * have contacted patients with fever or respiratory symptoms from communities with case reports within 14 days; * two or more cases of fever and / or respiratory symptoms in a small contact area of volunteers, such as home, office etc. within 14 days; * history of sars-cov-2 infection; * history of asthma, history of allergy to the vaccine or vaccine components, or serious adverse reactions to the vaccine, such as urticaria, dyspnea, and angioedema; * congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc.; * autoimmune disease or immunodeficiency / immunosuppression; * severe chronic diseases, severe cardiovascular diseases, hypertension and diabetes that cannot be controlled by drugs, liver or kidney diseases, malignant tumors, etc.; * severe neurological disease (epilepsy, convulsions or convulsions) or mental illness; * thyroid disease or history of thyroidectomy, spleenlessness, functional spleenlessness, spleenlessness or splenectomy resulting from any condition; * diagnosed abnormal blood coagulation function (eg, lack of blood coagulation factors, blood coagulopathy, abnormal platelets) or obvious bruising or blood coagulation; * immunosuppressive therapy, cytotoxic therapy, inhaled corticosteroids (excluding allergic rhinitis corticosteroid spray therapy, acute noncomplicated dermatitis superficial corticosteroid therapy) in the past 6 months; * physical examination has clinically significant abnormal hematology and biochemistry laboratory test results that exceed the reference value range (only applicable to phase i clinical trials): 1. blood routine test: white blood cell count, hemoglobin, platelet count; 2. detection of blood biochemical indicators: alanine aminotransferase (alt), aspartate aminotransferase (ast), total bilirubin (tbil), creatinine (cr), fasting blood glucose; 3. urine routine index: urine protein (pro); * history of alcohol or drug abuse; * receipt of blood products within in the past 3 months; * receipt of other investigational drugs in the past 30 days; * receipt of attenuated live vaccines in the past 14 days; * receipt of inactivated or subunit vaccines in the past 7 days; * acute diseases or acute exacerbation of chronic diseases in the past 7 days; * axillary temperature \>37.0°c; * already pregnant (including a positive urine pregnancy test) or are breastfeeding, planning to get pregnant within 3 months; * according to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.

travel history / residence history of communities with case reports within 14 days; history of contact with a sars-cov-2 infection (positive in nucleic acid test) within 14 days; have contacted patients with fever or respiratory symptoms from communities with case reports within 14 days; two or more cases of fever and / or respiratory symptoms in a small contact area of volunteers, such as home, office etc. within 14 days; history of sars-cov-2 infection; history of asthma, history of allergy to the vaccine or vaccine components, or serious adverse reactions to the vaccine, such as urticaria, dyspnea, and angioedema; congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc.; autoimmune disease or immunodeficiency / immunosuppression; severe chronic diseases, severe cardiovascular diseases, hypertension and diabetes that cannot be controlled by drugs, liver or kidney diseases, malignant tumors, etc.; severe neurological disease (epilepsy, convulsions or convulsions) or mental illness; thyroid disease or history of thyroidectomy, spleenlessness, functional spleenlessness, spleenlessness or splenectomy resulting from any condition; diagnosed abnormal blood coagulation function (eg, lack of blood coagulation factors, blood coagulopathy, abnormal platelets) or obvious bruising or blood coagulation; immunosuppressive therapy, cytotoxic therapy, inhaled corticosteroids (excluding allergic rhinitis corticosteroid spray therapy, acute noncomplicated dermatitis superficial corticosteroid therapy) in the past 6 months; physical examination has clinically significant abnormal hematology and biochemistry laboratory test results that exceed the reference value range (only applicable to phase i clinical trials): blood routine test: white blood cell count, hemoglobin, platelet count; detection of blood biochemical indicators: alanine aminotransferase (alt), aspartate aminotransferase (ast), total bilirubin (tbil), creatinine (cr), fasting blood glucose; urine routine index: urine protein (pro); history of alcohol or drug abuse; receipt of blood products within in the past 3 months; receipt of other investigational drugs in the past 30 days; receipt of attenuated live vaccines in the past 14 days; receipt of inactivated or subunit vaccines in the past 7 days; acute diseases or acute exacerbation of chronic diseases in the past 7 days; axillary temperature >37.0°c; already pregnant (including a positive urine pregnancy test) or are breastfeeding, planning to get pregnant within 3 months; according to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.

travel history / residence history of communities with case reports within 14 days; history of contact with a sars-cov-2 infection (positive in nucleic acid test) within 14 days; have contacted patients with fever or respiratory symptoms from communities with case reports within 14 days; two or more cases of fever and / or respiratory symptoms in a small contact area of volunteers, such as home, office etc. within 14 days; history of sars-cov-2 infection; history of asthma, history of allergy to the vaccine or vaccine components, or serious adverse reactions to the vaccine, such as urticaria, dyspnea, and angioedema; congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc.; autoimmune disease or immunodeficiency / immunosuppression; severe chronic diseases, severe cardiovascular diseases, hypertension and diabetes that cannot be controlled by drugs, liver or kidney diseases, malignant tumors, etc.; severe neurological disease (epilepsy, convulsions or convulsions) or mental illness; thyroid disease or history of thyroidectomy, spleenlessness, functional spleenlessness, spleenlessness or splenectomy resulting from any condition; diagnosed abnormal blood coagulation function (eg, lack of blood coagulation factors, blood coagulopathy, abnormal platelets) or obvious bruising or blood coagulation; immunosuppressive therapy, cytotoxic therapy, inhaled corticosteroids (excluding allergic rhinitis corticosteroid spray therapy, acute noncomplicated dermatitis superficial corticosteroid therapy) in the past 6 months; physical examination has clinically significant abnormal hematology and biochemistry laboratory test results that exceed the reference value range (only applicable to phase i clinical trials): blood routine test: white blood cell count, hemoglobin, platelet count; detection of blood biochemical indicators: alanine aminotransferase (alt), aspartate aminotransferase (ast), total bilirubin (tbil), creatinine (cr), fasting blood glucose; urine routine index: urine protein (pro); history of alcohol or drug abuse; receipt of blood products within in the past 3 months; receipt of other investigational drugs in the past 30 days; receipt of attenuated live vaccines in the past 14 days; receipt of inactivated or subunit vaccines in the past 7 days; acute diseases or acute exacerbation of chronic diseases in the past 7 days; axillary temperature >37.0°c; already pregnant (including a positive urine pregnancy test) or are breastfeeding, planning to get pregnant within 3 months; according to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.

- travel history / residence history of communities with case reports within 14 days; - history of contact with a sars-cov-2 infection (positive in nucleic acid test) within 14 days; - have contacted patients with fever or respiratory symptoms from communities with case reports within 14 days; - two or more cases of fever and / or respiratory symptoms in a small contact area of volunteers, such as home, office etc. within 14 days; - history of sars-cov-2 infection; - history of asthma, history of allergy to the vaccine or vaccine components, or serious adverse reactions to the vaccine, such as urticaria, dyspnea, and angioedema; - congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc.; - autoimmune disease or immunodeficiency / immunosuppression; - severe chronic diseases, severe cardiovascular diseases, hypertension and diabetes that cannot be controlled by drugs, liver or kidney diseases, malignant tumors, etc.; - severe neurological disease (epilepsy, convulsions or convulsions) or mental illness; - thyroid disease or history of thyroidectomy, spleenlessness, functional spleenlessness, spleenlessness or splenectomy resulting from any condition; - diagnosed abnormal blood coagulation function (eg, lack of blood coagulation factors, blood coagulopathy, abnormal platelets) or obvious bruising or blood coagulation; - immunosuppressive therapy, cytotoxic therapy, inhaled corticosteroids (excluding allergic rhinitis corticosteroid spray therapy, acute noncomplicated dermatitis superficial corticosteroid therapy) in the past 6 months; - physical examination has clinically significant abnormal hematology and biochemistry laboratory test results that exceed the reference value range (only applicable to phase i clinical trials): 1. blood routine test: white blood cell count, hemoglobin, platelet count; 2. detection of blood biochemical indicators: alanine aminotransferase (alt), aspartate aminotransferase (ast), total bilirubin (tbil), creatinine (cr), fasting blood glucose; 3. urine routine index: urine protein (pro); - history of alcohol or drug abuse; - receipt of blood products within in the past 3 months; - receipt of other investigational drugs in the past 30 days; - receipt of attenuated live vaccines in the past 14 days; - receipt of inactivated or subunit vaccines in the past 7 days; - acute diseases or acute exacerbation of chronic diseases in the past 7 days; - axillary temperature >37.0°c; - already pregnant (including a positive urine pregnancy test) or are breastfeeding, planning to get pregnant within 3 months; - according to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.

- travel history / residence history of communities with case reports within 14 days; - history of contact with a sars-cov-2 infection (positive in nucleic acid test) within 14 days; - have contacted patients with fever or respiratory symptoms from communities with case reports within 14 days; - two or more cases of fever and / or respiratory symptoms in a small contact area of volunteers, such as home, office etc. within 14 days; - history of sars-cov-2 infection; - history of asthma, history of allergy to the vaccine or vaccine components, or serious adverse reactions to the vaccine, such as urticaria, dyspnea, and angioedema; - congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc.; - autoimmune disease or immunodeficiency / immunosuppression; - severe chronic diseases, severe cardiovascular diseases, hypertension and diabetes that cannot be controlled by drugs, liver or kidney diseases, malignant tumors, etc.; - severe neurological disease (epilepsy, convulsions or convulsions) or mental illness; - thyroid disease or history of thyroidectomy, spleenlessness, functional spleenlessness, spleenlessness or splenectomy resulting from any condition; - diagnosed abnormal blood coagulation function (eg, lack of blood coagulation factors, blood coagulopathy, abnormal platelets) or obvious bruising or blood coagulation; - immunosuppressive therapy, cytotoxic therapy, inhaled corticosteroids (excluding allergic rhinitis corticosteroid spray therapy, acute noncomplicated dermatitis superficial corticosteroid therapy) in the past 6 months; - physical examination has clinically significant abnormal hematology and biochemistry laboratory test results that exceed the reference value range (only applicable to phase i clinical trials): 1. blood routine test: white blood cell count, hemoglobin, platelet count; 2. detection of blood biochemical indicators: alanine aminotransferase (alt), aspartate aminotransferase (ast), total bilirubin (tbil), creatinine (cr), fasting blood glucose; 3. urine routine index: urine protein (pro); - history of alcohol or drug abuse; - receipt of blood products within in the past 3 months; - receipt of other investigational drugs in the past 30 days; - receipt of attenuated live vaccines in the past 14 days; - receipt of inactivated or subunit vaccines in the past 7 days; - acute diseases or acute exacerbation of chronic diseases in the past 7 days; - axillary temperature >37.0°c; - already pregnant (including a positive urine pregnancy test) or are breastfeeding, planning to get pregnant within 3 months; - according to the investigator's judgment, the subject has any other factors that are not suitable for participating in the clinical trial.