* confirmed cases, suspected cases or asymptomatic cases of covid-19; * with a history of severe acute respiratory syndrome (sars) and middle east respiratory syndrome (mers) (self-report, on-site inquiry); * has vaccinated with one or four doses and above covid-19 vaccine; * axillary temperature ≥37.3℃ (tympanic temperature ≥ 37.6 ℃); * previous allergic reactions to drug or vaccination (such as acute allergic reactions, urticaria, eczema, dyspnea, angioneurotic edema or abdominal pain) or allergy to known components of covid-19 vaccine (self-report, onsite enquiry); * have a history of hospital-diagnosed thrombocytopenia or other coagulation disorders (self-report, onsite enquiry); * with known immunological impairment or immunocompromised diagnosed by the hospital (self-report, onsite enquiry); * have an uncontrolled epilepsy and other progressive neurological diseases or a history of guillain-barre syndrome (self-report, onsite enquiry); * received whole blood, plasma and immunoglobulin therapy within 1 month (self-report, onsite enquiry); * known or suspected severe illness includes: respiratory illness, acute infection or active attacks of chronic illness, liver and kidney disease, severe diabetes mellitus, malignant tumor, infectious or allergic skin disease, human immunodeficiency virus (hiv) infection (self-report, onsite enquiry, provide test report if available); * with hospital-diagnosed serious cardiovascular diseases (cardiopulmonary failure, drug-uncontrolled hypertension (physical examination of systolic blood pressure ≥ 140 mmhg and/or diastolic blood pressure ≥ 90 mmhg), acute attacks of chronic respiratory illness (self-report, onsite enquiry); * received live attenuated vaccines within 1 month before vaccination (self-report, onsite enquiry); * received inactivated vaccines within 14 days before vaccination (self-report, onsite enquiry); * participating or planning to participate in other interventional vaccine clinical trials during this study * other vaccination-related contraindications considered by investigators.

* confirmed cases, suspected cases or asymptomatic cases of covid-19; * with a history of severe acute respiratory syndrome (sars) and middle east respiratory syndrome (mers) (self-report, on-site inquiry); * has vaccinated with one or four doses and above covid-19 vaccine; * axillary temperature ≥37.3℃ (tympanic temperature ≥ 37.6 ℃); * previous allergic reactions to drug or vaccination (such as acute allergic reactions, urticaria, eczema, dyspnea, angioneurotic edema or abdominal pain) or allergy to known components of covid-19 vaccine (self-report, onsite enquiry); * have a history of hospital-diagnosed thrombocytopenia or other coagulation disorders (self-report, onsite enquiry); * with known immunological impairment or immunocompromised diagnosed by the hospital (self-report, onsite enquiry); * have an uncontrolled epilepsy and other progressive neurological diseases or a history of guillain-barre syndrome (self-report, onsite enquiry); * received whole blood, plasma and immunoglobulin therapy within 1 month (self-report, onsite enquiry); * known or suspected severe illness includes: respiratory illness, acute infection or active attacks of chronic illness, liver and kidney disease, severe diabetes mellitus, malignant tumor, infectious or allergic skin disease, human immunodeficiency virus (hiv) infection (self-report, onsite enquiry, provide test report if available); * with hospital-diagnosed serious cardiovascular diseases (cardiopulmonary failure, drug-uncontrolled hypertension (physical examination of systolic blood pressure ≥ 140 mmhg and/or diastolic blood pressure ≥ 90 mmhg), acute attacks of chronic respiratory illness (self-report, onsite enquiry); * received live attenuated vaccines within 1 month before vaccination (self-report, onsite enquiry); * received inactivated vaccines within 14 days before vaccination (self-report, onsite enquiry); * participating or planning to participate in other interventional vaccine clinical trials during this study * other vaccination-related contraindications considered by investigators.

confirmed cases, suspected cases or asymptomatic cases of covid-19; with a history of severe acute respiratory syndrome (sars) and middle east respiratory syndrome (mers) (self-report, on-site inquiry); has vaccinated with one or four doses and above covid-19 vaccine; axillary temperature ≥37.3℃ (tympanic temperature ≥ 37.6 ℃); previous allergic reactions to drug or vaccination (such as acute allergic reactions, urticaria, eczema, dyspnea, angioneurotic edema or abdominal pain) or allergy to known components of covid-19 vaccine (self-report, onsite enquiry); have a history of hospital-diagnosed thrombocytopenia or other coagulation disorders (self-report, onsite enquiry); with known immunological impairment or immunocompromised diagnosed by the hospital (self-report, onsite enquiry); have an uncontrolled epilepsy and other progressive neurological diseases or a history of guillain-barre syndrome (self-report, onsite enquiry); received whole blood, plasma and immunoglobulin therapy within 1 month (self-report, onsite enquiry); known or suspected severe illness includes: respiratory illness, acute infection or active attacks of chronic illness, liver and kidney disease, severe diabetes mellitus, malignant tumor, infectious or allergic skin disease, human immunodeficiency virus (hiv) infection (self-report, onsite enquiry, provide test report if available); with hospital-diagnosed serious cardiovascular diseases (cardiopulmonary failure, drug-uncontrolled hypertension (physical examination of systolic blood pressure ≥ 140 mmhg and/or diastolic blood pressure ≥ 90 mmhg), acute attacks of chronic respiratory illness (self-report, onsite enquiry); received live attenuated vaccines within 1 month before vaccination (self-report, onsite enquiry); received inactivated vaccines within 14 days before vaccination (self-report, onsite enquiry); participating or planning to participate in other interventional vaccine clinical trials during this study other vaccination-related contraindications considered by investigators.

confirmed cases, suspected cases or asymptomatic cases of covid-19; with a history of severe acute respiratory syndrome (sars) and middle east respiratory syndrome (mers) (self-report, on-site inquiry); has vaccinated with one or four doses and above covid-19 vaccine; axillary temperature ≥37.3℃ (tympanic temperature ≥ 37.6 ℃); previous allergic reactions to drug or vaccination (such as acute allergic reactions, urticaria, eczema, dyspnea, angioneurotic edema or abdominal pain) or allergy to known components of covid-19 vaccine (self-report, onsite enquiry); have a history of hospital-diagnosed thrombocytopenia or other coagulation disorders (self-report, onsite enquiry); with known immunological impairment or immunocompromised diagnosed by the hospital (self-report, onsite enquiry); have an uncontrolled epilepsy and other progressive neurological diseases or a history of guillain-barre syndrome (self-report, onsite enquiry); received whole blood, plasma and immunoglobulin therapy within 1 month (self-report, onsite enquiry); known or suspected severe illness includes: respiratory illness, acute infection or active attacks of chronic illness, liver and kidney disease, severe diabetes mellitus, malignant tumor, infectious or allergic skin disease, human immunodeficiency virus (hiv) infection (self-report, onsite enquiry, provide test report if available); with hospital-diagnosed serious cardiovascular diseases (cardiopulmonary failure, drug-uncontrolled hypertension (physical examination of systolic blood pressure ≥ 140 mmhg and/or diastolic blood pressure ≥ 90 mmhg), acute attacks of chronic respiratory illness (self-report, onsite enquiry); received live attenuated vaccines within 1 month before vaccination (self-report, onsite enquiry); received inactivated vaccines within 14 days before vaccination (self-report, onsite enquiry); participating or planning to participate in other interventional vaccine clinical trials during this study other vaccination-related contraindications considered by investigators.

confirmed cases, suspected cases or asymptomatic cases of covid-19; with a history of sars and mers infection (self-report, on-site inquiry); has vaccinated with one or four doses and above covid-19 vaccine; axillary temperature ≥37.3℃ (tympanic temperature ≥ 37.6 ℃); previous allergic reactions to drug or vaccination (such as acute allergic reactions, urticaria, eczema, dyspnea, angioneurotic edema or abdominal pain) or allergy to known components of covid-19 vaccine (self-report, onsite enquiry); have a history of hospital-diagnosed thrombocytopenia or other coagulation disorders (self-report, onsite enquiry); with known immunological impairment or immunocompromised diagnosed by the hospital (self-report, onsite enquiry); have an uncontrolled epilepsy and other progressive neurological diseases or a history of guillain-barre syndrome (self-report, onsite enquiry); received whole blood, plasma and immunoglobulin therapy within 1 month (self-report, onsite enquiry); known or suspected severe illness includes: respiratory illness, acute infection or active attacks of chronic illness, liver and kidney disease, severe diabetes mellitus, malignant tumor, infectious or allergic skin disease, human immunodeficiency virus (hiv) infection (self-report, onsite enquiry, provide test report if available); with hospital-diagnosed serious cardiovascular diseases (cardiopulmonary failure, drug-uncontrolled hypertension (physical examination of systolic blood pressure ≥ 140 mmhg and/or diastolic blood pressure ≥ 90 mmhg), acute attacks of chronic respiratory illness (self-report, onsite enquiry); received live attenuated vaccines within 1 month before vaccination (self-report, onsite enquiry); received inactivated vaccines within 14 days before vaccination (self-report, onsite enquiry); participating or planning to participate in other interventional vaccine clinical trials during this study other vaccination-related contraindications considered by investigators.

confirmed cases, suspected cases or asymptomatic cases of covid-19; with a history of sars and mers infection (self-report, on-site inquiry); has vaccinated with one or four doses and above covid-19 vaccine; axillary temperature ≥37.3℃ (tympanic temperature ≥ 37.6 ℃); previous allergic reactions to drug or vaccination (such as acute allergic reactions, urticaria, eczema, dyspnea, angioneurotic edema or abdominal pain) or allergy to known components of covid-19 vaccine (self-report, onsite enquiry); have a history of hospital-diagnosed thrombocytopenia or other coagulation disorders (self-report, onsite enquiry); with known immunological impairment or immunocompromised diagnosed by the hospital (self-report, onsite enquiry); have an uncontrolled epilepsy and other progressive neurological diseases or a history of guillain-barre syndrome (self-report, onsite enquiry); received whole blood, plasma and immunoglobulin therapy within 1 month (self-report, onsite enquiry); known or suspected severe illness includes: respiratory illness, acute infection or active attacks of chronic illness, liver and kidney disease, severe diabetes mellitus, malignant tumor, infectious or allergic skin disease, human immunodeficiency virus (hiv) infection (self-report, onsite enquiry, provide test report if available); with hospital-diagnosed serious cardiovascular diseases (cardiopulmonary failure, drug-uncontrolled hypertension (physical examination of systolic blood pressure ≥ 140 mmhg and/or diastolic blood pressure ≥ 90 mmhg), acute attacks of chronic respiratory illness (self-report, onsite enquiry); received live attenuated vaccines within 1 month before vaccination (self-report, onsite enquiry); received inactivated vaccines within 14 days before vaccination (self-report, onsite enquiry); participating or planning to participate in other interventional vaccine clinical trials during this study other vaccination-related contraindications considered by investigators.