1. Having a history of COVID-19 or a positive nucleic acid test for COVID-19, 2. Having a history or a family history of allergy, convulsion, epilepsy, brain disease, or mental illness, 3. Being allergic to any component of vaccines, or having a history of severe allergic reaction to any vaccine, 4. Having immunodeficiency disorder, during treatment of malignant tumor, having immunodeficiency induced by immunosuppressants (oral steroid hormones) or HIV, or having a family member with close contact who suffers from congenital immune disorder, 5. Having injection of non-specific immunoglobulin within 1 month prior to enrollment, 6. Having acute febrile illness or communicable disease, 7. Having a history of confirmed thrombocytopenia or other coagulation disorders, which may cause contraindications for a subcutaneous injection, 8. Having severe chronic disease or acute exacerbation of chronic disease, or having uncontrolled hypertension or diabetes, 9. Having various infectious, pyogenic, or allergic skin diseases, 10. Women in pregnancy or lactation or participants who plan for a baby within 3 months after vaccination should delay the vaccination, 11. Having any condition that may affect trial assessment as determined by researchers.

1. Having a history of COVID-19 or a positive nucleic acid test for COVID-19, 2. Having a history or a family history of allergy, convulsion, epilepsy, brain disease, or mental illness, 3. Being allergic to any component of vaccines, or having a history of severe allergic reaction to any vaccine, 4. Having immunodeficiency disorder, during treatment of malignant tumor, having immunodeficiency induced by immunosuppressants (oral steroid hormones) or HIV, or having a family member with close contact who suffers from congenital immune disorder, 5. Having injection of non-specific immunoglobulin within 1 month prior to enrollment, 6. Having acute febrile illness or communicable disease, 7. Having a history of confirmed thrombocytopenia or other coagulation disorders, which may cause contraindications for a subcutaneous injection, 8. Having severe chronic disease or acute exacerbation of chronic disease, or having uncontrolled hypertension or diabetes, 9. Having various infectious, pyogenic, or allergic skin diseases, 10. Women in pregnancy or lactation or participants who plan for a baby within 3 months after vaccination should delay the vaccination, 11. Having any condition that may affect trial assessment as determined by researchers.