- confirmed or asymptomatic covid-19 cases or sars-cov-2 infection(had positive in sars-cov-2 nucleic acid test or serological test). - had a history of traveling or residence in domestic area of high pandemic risk, overseas or epidemic areas, or had a history of contact with confirmed, asymptomatic or suspected covid-19 cases within the past 14 days; - history of sars; - received sars-cov-2 vaccines for emergency use or approved sars-cov-2 vaccines; - individuals involving a clinical study within 6 months prior to the screening visit; or planning to participate in another clinical study during study period. - individual's systolic blood pressure ≥ 150mmhg and/or diastolic blood pressure ≥ 100mmhg at screening visit - axillary temperature >=37.3℃ prior to vaccination - individuals in other acute diseases, or in the acute phase of chronic diseases within 3 days prior to the signing of the informed consent form. - received immunoglobulin and/or blood product 3 months prior to the first vaccination. - presence of uncontrolled chronic pulmonary, cardiovascular, renal, hepatic, neurologic, hematologic or metabolic (including diabetes mellitus) disorders, which would include the potential subject in a high-risk category for sars-cov-2 infection and/or its complications as judged by the investigator. - individuals with a history of severe allergic reaction (throat swelling, difficult in breath, dyspnea, or shock). - individuals who have a history of severe adverse reaction associated with a vaccine or severe allergic reaction [e.g., anaphylaxis to any component of the study vaccines (s protein, aluminum hydroxide, cpg adjuvant). - any autoimmune or immunodeficiency disease/condition [e.g. human immunodeficiency virus (hiv) infection, systemic lupus erythematosus (sle)] - received immunoglobulin, blood-derived products within 3 months prior to the first study vaccination. - abnormal coagulation function (such as coagulation factor deficiency, coagulation disease, platelet abnormality) obvious bruises or coagulopathy. - pregnant women or breastfeeding women. - according to the judgment of the investigator, subject has or had any other symptoms, medical history and other factors that are not suitable for participating in this clinical trial.

- confirmed or asymptomatic covid-19 cases or sars-cov-2 infection(had positive in sars-cov-2 nucleic acid test or serological test). - had a history of traveling or residence in domestic area of high pandemic risk, overseas or epidemic areas, or had a history of contact with confirmed, asymptomatic or suspected covid-19 cases within the past 14 days; - history of sars; - received sars-cov-2 vaccines for emergency use or approved sars-cov-2 vaccines; - individuals involving a clinical study within 6 months prior to the screening visit; or planning to participate in another clinical study during study period. - individual's systolic blood pressure ≥ 150mmhg and/or diastolic blood pressure ≥ 100mmhg at screening visit - axillary temperature >=37.3℃ prior to vaccination - individuals in other acute diseases, or in the acute phase of chronic diseases within 3 days prior to the signing of the informed consent form. - received immunoglobulin and/or blood product 3 months prior to the first vaccination. - presence of uncontrolled chronic pulmonary, cardiovascular, renal, hepatic, neurologic, hematologic or metabolic (including diabetes mellitus) disorders, which would include the potential subject in a high-risk category for sars-cov-2 infection and/or its complications as judged by the investigator. - individuals with a history of severe allergic reaction (throat swelling, difficult in breath, dyspnea, or shock). - individuals who have a history of severe adverse reaction associated with a vaccine or severe allergic reaction [e.g., anaphylaxis to any component of the study vaccines (s protein, aluminum hydroxide, cpg adjuvant). - any autoimmune or immunodeficiency disease/condition [e.g. human immunodeficiency virus (hiv) infection, systemic lupus erythematosus (sle)] - received immunoglobulin, blood-derived products within 3 months prior to the first study vaccination. - abnormal coagulation function (such as coagulation factor deficiency, coagulation disease, platelet abnormality) obvious bruises or coagulopathy. - pregnant women or breastfeeding women. - according to the judgment of the investigator, subject has or had any other symptoms, medical history and other factors that are not suitable for participating in this clinical trial.