* pregnancy, lactation, or intention to become pregnant during the vaccination phase through three months after the booster dose. * prior receipt/ planned receipt of any vaccine other than the study intervention within 28 days before and after each study vaccination. * previous participation in any covid-19 vaccination trial or vaccination campaign. * administration of immunoglobulins and/ or any blood products within the three months preceding the administration of the study vaccine. * known infection with hepatitis b, c virus. * known history of allergy or anaphylaxis to study vaccine components and/or excipients or other medications, or any other allergies deemed by the investigator to increase the risk of an adverse reaction. * history of bleeding disorder (e.g., factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following im injections or venipuncture. * continuous use of the anticoagulants, such as coumarins and related anticoagulants. * severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, renal disease, liver disease, endocrine disorders, and neurological illness (mild/moderate well controlled comorbidities are allowed). * any clinically significant abnormal finding on screening as judged by the investigator. * confirmed sars-cov-2 infection at enrollment. * any confirmed or suspected immunosuppressive or immunodeficient state, asplenia, recurrent severe infections and chronic use (more than 14 days) immunosuppressant medication within 3 months prior to recruitment (topical steroids are allowed). * any other finding which in the opinion of the investigators would increase the risk of an adverse outcome from participation in the trial or result in incomplete or poor-quality data.

* pregnancy, lactation, or intention to become pregnant during the vaccination phase through three months after the booster dose. * prior receipt/ planned receipt of any vaccine other than the study intervention within 28 days before and after each study vaccination. * previous participation in any covid-19 vaccination trial or vaccination campaign. * administration of immunoglobulins and/ or any blood products within the three months preceding the administration of the study vaccine. * known infection with hepatitis b, c virus. * known history of allergy or anaphylaxis to study vaccine components and/or excipients or other medications, or any other allergies deemed by the investigator to increase the risk of an adverse reaction. * history of bleeding disorder (e.g., factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following im injections or venipuncture. * continuous use of the anticoagulants, such as coumarins and related anticoagulants. * severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, renal disease, liver disease, endocrine disorders, and neurological illness (mild/moderate well controlled comorbidities are allowed). * any clinically significant abnormal finding on screening as judged by the investigator. * confirmed sars-cov-2 infection at enrollment. * any confirmed or suspected immunosuppressive or immunodeficient state, asplenia, recurrent severe infections and chronic use (more than 14 days) immunosuppressant medication within 3 months prior to recruitment (topical steroids are allowed). * any other finding which in the opinion of the investigators would increase the risk of an adverse outcome from participation in the trial or result in incomplete or poor-quality data.

pregnancy, lactation, or intention to become pregnant during the vaccination phase through three months after the booster dose. prior receipt/ planned receipt of any vaccine other than the study intervention within 28 days before and after each study vaccination. previous participation in any covid-19 vaccination trial or vaccination campaign. administration of immunoglobulins and/ or any blood products within the three months preceding the administration of the study vaccine. known infection with hepatitis b, c virus. known history of allergy or anaphylaxis to study vaccine components and/or excipients or other medications, or any other allergies deemed by the investigator to increase the risk of an adverse reaction. history of bleeding disorder (e.g., factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following im injections or venipuncture. continuous use of the anticoagulants, such as coumarins and related anticoagulants. severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, renal disease, liver disease, endocrine disorders, and neurological illness (mild/moderate well controlled comorbidities are allowed). any clinically significant abnormal finding on screening as judged by the investigator. confirmed sars-cov-2 infection at enrollment. any confirmed or suspected immunosuppressive or immunodeficient state, asplenia, recurrent severe infections and chronic use (more than 14 days) immunosuppressant medication within 3 months prior to recruitment (topical steroids are allowed). any other finding which in the opinion of the investigators would increase the risk of an adverse outcome from participation in the trial or result in incomplete or poor-quality data.

pregnancy, lactation, or intention to become pregnant during the vaccination phase through three months after the booster dose. prior receipt/ planned receipt of any vaccine other than the study intervention within 28 days before and after each study vaccination. previous participation in any covid-19 vaccination trial or vaccination campaign. administration of immunoglobulins and/ or any blood products within the three months preceding the administration of the study vaccine. known infection with hepatitis b, c virus. known history of allergy or anaphylaxis to study vaccine components and/or excipients or other medications, or any other allergies deemed by the investigator to increase the risk of an adverse reaction. history of bleeding disorder (e.g., factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following im injections or venipuncture. continuous use of the anticoagulants, such as coumarins and related anticoagulants. severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, renal disease, liver disease, endocrine disorders, and neurological illness (mild/moderate well controlled comorbidities are allowed). any clinically significant abnormal finding on screening as judged by the investigator. confirmed sars-cov-2 infection at enrollment. any confirmed or suspected immunosuppressive or immunodeficient state, asplenia, recurrent severe infections and chronic use (more than 14 days) immunosuppressant medication within 3 months prior to recruitment (topical steroids are allowed). any other finding which in the opinion of the investigators would increase the risk of an adverse outcome from participation in the trial or result in incomplete or poor-quality data.

pregnancy, lactation, or intention to become pregnant during the vaccination phase through three months after the booster dose. prior receipt/ planned receipt of any vaccine other than the study intervention within 28 days before and after each study vaccination. previous participation in any covid-19 vaccination trial or vaccination campaign. administration of immunoglobulins and/ or any blood products within the three months preceding the administration of the study vaccine. known infection with hepatitis b, c virus. known history of allergy or anaphylaxis to study vaccine components and/or excipients or other medications, or any other allergies deemed by the investigator to increase the risk of an adverse reaction. history of bleeding disorder (e.g., factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following im injections or venipuncture. continuous use of the anticoagulants, such as coumarins and related anticoagulants. severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, renal disease, liver disease, endocrine disorders, and neurological illness (mild/moderate well controlled comorbidities are allowed). any clinically significant abnormal finding on screening as judged by the investigator. history of laboratory confirmed covid-19 illness prior to enrollment (history of sars-cov-2 detection by pcr or antibody to sars-cov-2) within past 12 months. sars-cov-2 seropositivity at screening. any confirmed or suspected immunosuppressive or immunodeficient state, asplenia, recurrent severe infections and chronic use (more than 14 days) immunosuppressant medication within 3 months prior to recruitment (topical steroids are allowed). any other finding which in the opinion of the investigators would increase the risk of an adverse outcome from participation in the trial or result in incomplete or poor-quality data.

pregnancy, lactation, or intention to become pregnant during the vaccination phase through three months after the booster dose. prior receipt/ planned receipt of any vaccine other than the study intervention within 28 days before and after each study vaccination. previous participation in any covid-19 vaccination trial or vaccination campaign. administration of immunoglobulins and/ or any blood products within the three months preceding the administration of the study vaccine. known infection with hepatitis b, c virus. known history of allergy or anaphylaxis to study vaccine components and/or excipients or other medications, or any other allergies deemed by the investigator to increase the risk of an adverse reaction. history of bleeding disorder (e.g., factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following im injections or venipuncture. continuous use of the anticoagulants, such as coumarins and related anticoagulants. severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, renal disease, liver disease, endocrine disorders, and neurological illness (mild/moderate well controlled comorbidities are allowed). any clinically significant abnormal finding on screening as judged by the investigator. history of laboratory confirmed covid-19 illness prior to enrollment (history of sars-cov-2 detection by pcr or antibody to sars-cov-2) within past 12 months. sars-cov-2 seropositivity at screening. any confirmed or suspected immunosuppressive or immunodeficient state, asplenia, recurrent severe infections and chronic use (more than 14 days) immunosuppressant medication within 3 months prior to recruitment (topical steroids are allowed). any other finding which in the opinion of the investigators would increase the risk of an adverse outcome from participation in the trial or result in incomplete or poor-quality data.

- pregnancy, lactation, or intention to become pregnant during the vaccination phase through three months after the booster dose. - prior receipt/ planned receipt of any vaccine other than the study intervention within 28 days before and after each study vaccination. - previous participation in any covid-19 vaccination trial or vaccination campaign. - administration of immunoglobulins and/ or any blood products within the three months preceding the administration of the study vaccine. - known infection with hepatitis b, c virus. - known history of allergy or anaphylaxis to study vaccine components and/or excipients or other medications, or any other allergies deemed by the investigator to increase the risk of an adverse reaction. - history of bleeding disorder (e.g., factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following im injections or venipuncture. - continuous use of the anticoagulants, such as coumarins and related anticoagulants. - severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, renal disease, liver disease, endocrine disorders, and neurological illness (mild/moderate well controlled comorbidities are allowed). - any clinically significant abnormal finding on screening as judged by the investigator. - history of laboratory confirmed covid-19 illness prior to enrollment (history of sars-cov-2 detection by pcr or antibody to sars-cov-2). - sars-cov-2 seropositivity at screening. - any confirmed or suspected immunosuppressive or immunodeficient state, asplenia, recurrent severe infections and chronic use (more than 14 days) immunosuppressant medication within 3 months prior to recruitment (topical steroids are allowed). - any other finding which in the opinion of the investigators would increase the risk of an adverse outcome from participation in the trial or result in incomplete or poor-quality data.

- pregnancy, lactation, or intention to become pregnant during the vaccination phase through three months after the booster dose. - prior receipt/ planned receipt of any vaccine other than the study intervention within 28 days before and after each study vaccination. - previous participation in any covid-19 vaccination trial or vaccination campaign. - administration of immunoglobulins and/ or any blood products within the three months preceding the administration of the study vaccine. - known infection with hepatitis b, c virus. - known history of allergy or anaphylaxis to study vaccine components and/or excipients or other medications, or any other allergies deemed by the investigator to increase the risk of an adverse reaction. - history of bleeding disorder (e.g., factor deficiency, coagulopathy or platelet disorder), or prior history of significant bleeding or bruising following im injections or venipuncture. - continuous use of the anticoagulants, such as coumarins and related anticoagulants. - severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, renal disease, liver disease, endocrine disorders, and neurological illness (mild/moderate well controlled comorbidities are allowed). - any clinically significant abnormal finding on screening as judged by the investigator. - history of laboratory confirmed covid-19 illness prior to enrollment (history of sars-cov-2 detection by pcr or antibody to sars-cov-2). - sars-cov-2 seropositivity at screening. - any confirmed or suspected immunosuppressive or immunodeficient state, asplenia, recurrent severe infections and chronic use (more than 14 days) immunosuppressant medication within 3 months prior to recruitment (topical steroids are allowed). - any other finding which in the opinion of the investigators would increase the risk of an adverse outcome from participation in the trial or result in incomplete or poor-quality data.