- rt-qpcr detects active sars-cov-2 infection; - a history of covid-19, sars, mers infection (self-report, on-site inquiry); - a high-risk factor for covid-19 infection: - a history of close contact with people infected with the new coronavirus, a history of living in high-risk areas, and a history of contact with patients with fever or respiratory symptoms in high-risk areas or abroad. - fever, dry cough, fatigue, nasal congestion, runny nose, sore throat, myalgia, diarrhea, shortness of breath, dyspnea, etc. 7 days before enrollment; - receiving covid-19 booster vaccination; - allergic to the active ingredients of the sars-cov-2 vaccine, any of the inactive ingredients, the substances used in the production process, or those who have had allergies during previous vaccination of similar vaccines; - those who have had severe allergic reactions to vaccines in the past (such as acute allergic reactions, angioedema, respiratory difficulties, urticaria, angioedema or abdominal pain); - body temperature >37.0℃ before vaccination; - blood pregnancy test positive; - with uncontrolled epilepsy and other serious neurological diseases (such as transmissive myelitis, guillain-barre syndrome) , demyelinating diseases, etc.), or have a history or family history of encephalopathy or mental disease; - severe liver and kidney disease, uncontrollable hypertension (systolic blood pressure ≥180 mmhg, diastolic blood pressure ≥100 mmhg), diabetic complications, malignant tumors, various acute diseases or acute attacks of chronic diseases; - diagnosed with congenital or acquired immunodeficiency, hiv infection, lymphoma, leukemia or other autoimmune diseases; - receiving anti-tuberculosis treatment; - a history of coagulopathy ( such as coagulation factor deficiency, coagulation disease) within 3 months of subjects receiving immunotherapy or inhibitor therapy (continuous oral or infusion for more than 14 days), or after 3 months of hormone therapy, the average daily dose is ≥20mg/day (prednisone); - receiving live attenuated vaccine within 1 month before this vaccination, other vaccines within 14 days before this vaccination; - receiving other research drugs within 3 months before vaccination; participating in other research vaccines or subjects in clinical trials of research drugs; - other conditions that the investigator judges are not suitable for this clinical trial;

- rt-qpcr detects active sars-cov-2 infection; - a history of covid-19, sars, mers infection (self-report, on-site inquiry); - a high-risk factor for covid-19 infection: - a history of close contact with people infected with the new coronavirus, a history of living in high-risk areas, and a history of contact with patients with fever or respiratory symptoms in high-risk areas or abroad. - fever, dry cough, fatigue, nasal congestion, runny nose, sore throat, myalgia, diarrhea, shortness of breath, dyspnea, etc. 7 days before enrollment; - receiving covid-19 booster vaccination; - allergic to the active ingredients of the sars-cov-2 vaccine, any of the inactive ingredients, the substances used in the production process, or those who have had allergies during previous vaccination of similar vaccines; - those who have had severe allergic reactions to vaccines in the past (such as acute allergic reactions, angioedema, respiratory difficulties, urticaria, angioedema or abdominal pain); - body temperature >37.0℃ before vaccination; - blood pregnancy test positive; - with uncontrolled epilepsy and other serious neurological diseases (such as transmissive myelitis, guillain-barre syndrome) , demyelinating diseases, etc.), or have a history or family history of encephalopathy or mental disease; - severe liver and kidney disease, uncontrollable hypertension (systolic blood pressure ≥180 mmhg, diastolic blood pressure ≥100 mmhg), diabetic complications, malignant tumors, various acute diseases or acute attacks of chronic diseases; - diagnosed with congenital or acquired immunodeficiency, hiv infection, lymphoma, leukemia or other autoimmune diseases; - receiving anti-tuberculosis treatment; - a history of coagulopathy ( such as coagulation factor deficiency, coagulation disease) within 3 months of subjects receiving immunotherapy or inhibitor therapy (continuous oral or infusion for more than 14 days), or after 3 months of hormone therapy, the average daily dose is ≥20mg/day (prednisone); - receiving live attenuated vaccine within 1 month before this vaccination, other vaccines within 14 days before this vaccination; - receiving other research drugs within 3 months before vaccination; participating in other research vaccines or subjects in clinical trials of research drugs; - other conditions that the investigator judges are not suitable for this clinical trial;