- previously confirmed or asymptomatic covid-19 patient. - has been immunized with a sars-cov-2 vaccine. - illiterate. - known allergy to any ingredient (including excipient) of this product. - received non-specific immunoglobulin injection within 1 month before enrollment. - received a live attenuated vaccine within 1 month before immunization or other vaccine within 14 days before immunization. - previous serious allergy to vaccine (e.g., acute allergic reaction, urticaria, angioedema, and dyspnea). - has uncontrolled epilepsy and other progressive neurological disorders; history of guillain-barré syndrome. - severe respiratory disorders, severe hepatic and renal diseases, malignancies, and various acute diseases or acute onset of chronic diseases. - diagnosed with congenital or acquired immunodeficiency, hiv infection, lymphoma, leukemia, or other autoimmune diseases. - definitively diagnosed with thrombocytopenia or history of other coagulation disorders that may cause subcutaneous injection to be contraindicated. - currently experiencing acute complications (ketoacidosis, hyperosmolar state, lactic acidosis, etc.) of diabetes; or within 2 weeks after recovery from these complications. - other physical conditions judged by the investigator that render the patient unsuitable for participation in the clinical study.

- previously confirmed or asymptomatic covid-19 patient. - has been immunized with a sars-cov-2 vaccine. - illiterate. - known allergy to any ingredient (including excipient) of this product. - received non-specific immunoglobulin injection within 1 month before enrollment. - received a live attenuated vaccine within 1 month before immunization or other vaccine within 14 days before immunization. - previous serious allergy to vaccine (e.g., acute allergic reaction, urticaria, angioedema, and dyspnea). - has uncontrolled epilepsy and other progressive neurological disorders; history of guillain-barré syndrome. - severe respiratory disorders, severe hepatic and renal diseases, malignancies, and various acute diseases or acute onset of chronic diseases. - diagnosed with congenital or acquired immunodeficiency, hiv infection, lymphoma, leukemia, or other autoimmune diseases. - definitively diagnosed with thrombocytopenia or history of other coagulation disorders that may cause subcutaneous injection to be contraindicated. - currently experiencing acute complications (ketoacidosis, hyperosmolar state, lactic acidosis, etc.) of diabetes; or within 2 weeks after recovery from these complications. - other physical conditions judged by the investigator that render the patient unsuitable for participation in the clinical study.