the participant may not enter in the trial if any of the following apply: * pregnant women or those who are planning to conceive within next 70 days. * women who are breast feeding * already received any covid-19 vaccine or any other vaccine likely to impact on interpretation of the trial data (e.g., adenovirus vectored vaccines). * administration of immunoglobulins and/or any blood products within the three months preceding the planned administration of the vaccines. * any confirmed or suspected immunosuppressive or immunodeficient state; asplenia; recurrent severe infections and use of immunosuppressant medication within the past 6 months, except topical steroids or short-term oral steroids (course lasting ≤14 days) * history of allergic disease or reactions likely to be exacerbated by any component of study vaccines (e.g., hypersensitivity to the active substance of the covid-19 vaccines included in the study groups * any history of anaphylaxis. * current diagnosis of or treatment for cancer (except basal cell carcinoma of the skin and cervical carcinoma in situ) * bleeding disorder (e.g., factor deficiency, coagulopathy, or platelet disorder), or prior history of thrombotic events and/or significant bleeding or bruising following im injections or venipuncture. * continuous use of anticoagulants, such as coumarins and related anticoagulants (i.e., warfarin) * any other significant disease, disorder or finding which may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study data. * severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, liver disease, renal disease, endocrine disorder, and neurological illness (mild/moderate well controlled comorbidities are allowed) * history of active or previous auto-immune neurological disorders (e.g., multiple sclerosis, guillain-barre syndrome, transverse myelitis). bell's palsy will not be an exclusion criterion. * history of laboratory confirmed covid-19 within 6 months prior to enrolment (history of sars-cov-2 detection by pcr or antibody to sars-cov-2). * scheduled elective surgery during the trial. * participants enrolled in any other research trial. * participants planning to migrate out of the study area within 2 years of the study. temporary

the participant may not enter in the trial if any of the following apply: * pregnant women or those who are planning to conceive within next 70 days. * women who are breast feeding * already received any covid-19 vaccine or any other vaccine likely to impact on interpretation of the trial data (e.g., adenovirus vectored vaccines). * administration of immunoglobulins and/or any blood products within the three months preceding the planned administration of the vaccines. * any confirmed or suspected immunosuppressive or immunodeficient state; asplenia; recurrent severe infections and use of immunosuppressant medication within the past 6 months, except topical steroids or short-term oral steroids (course lasting ≤14 days) * history of allergic disease or reactions likely to be exacerbated by any component of study vaccines (e.g., hypersensitivity to the active substance of the covid-19 vaccines included in the study groups * any history of anaphylaxis. * current diagnosis of or treatment for cancer (except basal cell carcinoma of the skin and cervical carcinoma in situ) * bleeding disorder (e.g., factor deficiency, coagulopathy, or platelet disorder), or prior history of thrombotic events and/or significant bleeding or bruising following im injections or venipuncture. * continuous use of anticoagulants, such as coumarins and related anticoagulants (i.e., warfarin) * any other significant disease, disorder or finding which may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study data. * severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, liver disease, renal disease, endocrine disorder, and neurological illness (mild/moderate well controlled comorbidities are allowed) * history of active or previous auto-immune neurological disorders (e.g., multiple sclerosis, guillain-barre syndrome, transverse myelitis). bell's palsy will not be an exclusion criterion. * history of laboratory confirmed covid-19 within 6 months prior to enrolment (history of sars-cov-2 detection by pcr or antibody to sars-cov-2). * scheduled elective surgery during the trial. * participants enrolled in any other research trial. * participants planning to migrate out of the study area within 2 years of the study. temporary

the participant may not enter in the trial if any of the following apply: pregnant women or those who are planning to conceive within next 70 days. women who are breast feeding already received any covid-19 vaccine or any other vaccine likely to impact on interpretation of the trial data (e.g., adenovirus vectored vaccines). administration of immunoglobulins and/or any blood products within the three months preceding the planned administration of the vaccines. any confirmed or suspected immunosuppressive or immunodeficient state; asplenia; recurrent severe infections and use of immunosuppressant medication within the past 6 months, except topical steroids or short-term oral steroids (course lasting ≤14 days) history of allergic disease or reactions likely to be exacerbated by any component of study vaccines (e.g., hypersensitivity to the active substance of the covid-19 vaccines included in the study groups any history of anaphylaxis. current diagnosis of or treatment for cancer (except basal cell carcinoma of the skin and cervical carcinoma in situ) bleeding disorder (e.g., factor deficiency, coagulopathy, or platelet disorder), or prior history of thrombotic events and/or significant bleeding or bruising following im injections or venipuncture. continuous use of anticoagulants, such as coumarins and related anticoagulants (i.e., warfarin) any other significant disease, disorder or finding which may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study data. severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, liver disease, renal disease, endocrine disorder, and neurological illness (mild/moderate well controlled comorbidities are allowed) history of active or previous auto-immune neurological disorders (e.g., multiple sclerosis, guillain-barre syndrome, transverse myelitis). bell's palsy will not be an exclusion criterion. history of laboratory confirmed covid-19 within 6 months prior to enrolment (history of sars-cov-2 detection by pcr or antibody to sars-cov-2). scheduled elective surgery during the trial. participants enrolled in any other research trial. participants planning to migrate out of the study area within 2 years of the study. temporary

the participant may not enter in the trial if any of the following apply: pregnant women or those who are planning to conceive within next 70 days. women who are breast feeding already received any covid-19 vaccine or any other vaccine likely to impact on interpretation of the trial data (e.g., adenovirus vectored vaccines). administration of immunoglobulins and/or any blood products within the three months preceding the planned administration of the vaccines. any confirmed or suspected immunosuppressive or immunodeficient state; asplenia; recurrent severe infections and use of immunosuppressant medication within the past 6 months, except topical steroids or short-term oral steroids (course lasting ≤14 days) history of allergic disease or reactions likely to be exacerbated by any component of study vaccines (e.g., hypersensitivity to the active substance of the covid-19 vaccines included in the study groups any history of anaphylaxis. current diagnosis of or treatment for cancer (except basal cell carcinoma of the skin and cervical carcinoma in situ) bleeding disorder (e.g., factor deficiency, coagulopathy, or platelet disorder), or prior history of thrombotic events and/or significant bleeding or bruising following im injections or venipuncture. continuous use of anticoagulants, such as coumarins and related anticoagulants (i.e., warfarin) any other significant disease, disorder or finding which may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study data. severe and/or uncontrolled cardiovascular disease, respiratory disease, gastrointestinal disease, liver disease, renal disease, endocrine disorder, and neurological illness (mild/moderate well controlled comorbidities are allowed) history of active or previous auto-immune neurological disorders (e.g., multiple sclerosis, guillain-barre syndrome, transverse myelitis). bell's palsy will not be an exclusion criterion. history of laboratory confirmed covid-19 within 6 months prior to enrolment (history of sars-cov-2 detection by pcr or antibody to sars-cov-2). scheduled elective surgery during the trial. participants enrolled in any other research trial. participants planning to migrate out of the study area within 2 years of the study. temporary