1) Subjects who tested positive for COVID-19 by a PCR test at screening,2) Subjects with COVID-19, or have a history of COVID-19 (based on the interview with subject),3) Close contacts with patients with COVID-19 (based on the interview with subject),4) Subjects with a history of overseas travel in and after January 2020 (based on the interview with subject),5) Subjects who have been received any vaccines against COVID-19 (including unapproved drugs),6) Subjects who have experienced documented anaphylaxis caused by an ingredient of the study product,7) Pregnant or possibly pregnant women, women desiring to become pregnant before the end of the examination 28 days after the second dose, and breastfeeding women,8) Patients with progressive ossifying fibrodysplasia,9) Patients having an underlying disease, such as serious cardiovascular diseases, serious renal diseases, serious hepatic diseases, serious hematological diseases, serious developmental disorders, serious respiratory diseases, serious diabetes mellitus, etc.,10) Subjects having experienced pyrexia or symptoms suggesting allergy, such as generalized exanthema, within 2 days after immunization (not applicable if the causative ingredient is confirmed not included in the study product),11) Subjects with a history of convulsions,12) Subjects having been diagnosed with immunodeficiency or having a close relative with congenital immunodeficiency,13) Subjects possibly being allergic to any ingredient of the study product, 14) Subjects who participated in another clinical trial and have received another investigational product (excluding placebo) within 4 months (120 days) prior to the date of the first dose of study product in this study, or those who plan to participate in another clinical trial during their participation in this study,15) Subjects who have received transfusion or a gamma globulin preparation within 3 months (90 days), or a bolus therapy (>=200 mg/kg) with a gamma globulin preparation within 6 months (180 days), prior to the date of the first dose of study product,16) Subject who have received any treatments that may affect the immune function within 6 months (180 days) prior to the date of the first dose of study product, including radiotherapy, immunosuppressants (except for external use), immunosuppressive therapy, antirheumatics, adrenocorticotropic hormones, or corticosteroids (treatment at prednisolone equivalent doses >=2 mg/kg/day for >=14 days, except for external use.),17) Subjects who are judged by the principal investigator or the subinvestigator as ineligible for the study as a result of the screening test, or18) Subject being otherwise ineligible for this study in the principal investigator's or subinvestigator's opinion.

1) Subjects who tested positive for COVID-19 by a PCR test at screening,2) Subjects with COVID-19, or have a history of COVID-19 (based on the interview with subject),3) Close contacts with patients with COVID-19 (based on the interview with subject),4) Subjects with a history of overseas travel in and after January 2020 (based on the interview with subject),5) Subjects who have been received any vaccines against COVID-19 (including unapproved drugs),6) Subjects who have experienced documented anaphylaxis caused by an ingredient of the study product,7) Pregnant or possibly pregnant women, women desiring to become pregnant before the end of the examination 28 days after the second dose, and breastfeeding women,8) Patients with progressive ossifying fibrodysplasia,9) Patients having an underlying disease, such as serious cardiovascular diseases, serious renal diseases, serious hepatic diseases, serious hematological diseases, serious developmental disorders, serious respiratory diseases, serious diabetes mellitus, etc.,10) Subjects having experienced pyrexia or symptoms suggesting allergy, such as generalized exanthema, within 2 days after immunization (not applicable if the causative ingredient is confirmed not included in the study product),11) Subjects with a history of convulsions,12) Subjects having been diagnosed with immunodeficiency or having a close relative with congenital immunodeficiency,13) Subjects possibly being allergic to any ingredient of the study product, 14) Subjects who participated in another clinical trial and have received another investigational product (excluding placebo) within 4 months (120 days) prior to the date of the first dose of study product in this study, or those who plan to participate in another clinical trial during their participation in this study,15) Subjects who have received transfusion or a gamma globulin preparation within 3 months (90 days), or a bolus therapy (>=200 mg/kg) with a gamma globulin preparation within 6 months (180 days), prior to the date of the first dose of study product,16) Subject who have received any treatments that may affect the immune function within 6 months (180 days) prior to the date of the first dose of study product, including radiotherapy, immunosuppressants (except for external use), immunosuppressive therapy, antirheumatics, adrenocorticotropic hormones, or corticosteroids (treatment at prednisolone equivalent doses >=2 mg/kg/day for >=14 days, except for external use.),17) Subjects who are judged by the principal investigator or the subinvestigator as ineligible for the study as a result of the screening test, or18) Subject being otherwise ineligible for this study in the principal investigator's or subinvestigator's opinion.