- is acutely ill or febrile 72 hours prior to or at screening. fever is defined as a body temperature ≥38.0°c/100.4°f. participants meeting this criterion may be rescheduled within the relevant window periods. afebrile participants with minor illnesses can be enrolled at the discretion of the investigator. - is pregnant or breastfeeding. - known history of sars-cov-2 infection. - prior administration of an investigational coronavirus (sars-cov, middle east respiratory syndrome [mers]-cov) vaccine or current/planned simultaneous participation in another interventional study to prevent or treat covid-19. - demonstrated inability to comply with the study procedures. - an immediate family member or household member of this study's personnel. - history of anaphylaxis, urticaria, or other significant adverse reaction requiring medical intervention after receipt of a vaccine. - bleeding disorder considered a contraindication to intramuscular injection or phlebotomy. - has received or plans to receive a vaccine within 28 days prior to the first dose (day 1) or plans to receive a non-study vaccine within 28 days prior to or after any dose of investigational product (except for seasonal influenza vaccine). - has participated in an interventional clinical study within 28 days prior to the day of enrollment. - immunosuppressive or immunodeficient state, including human immunodeficiency virus (hiv) infection, asplenia, and recurrent severe infections. - has received systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to screening (for corticosteroids ≥20 milligram (mg)/day of prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to screening. - has received systemic immunoglobulins or blood products within 3 months prior to the day of screening. - has donated ≥450 milliliters (ml) of blood products within 28 days prior to screening.

- is acutely ill or febrile 72 hours prior to or at screening. fever is defined as a body temperature ≥38.0°c/100.4°f. participants meeting this criterion may be rescheduled within the relevant window periods. afebrile participants with minor illnesses can be enrolled at the discretion of the investigator. - is pregnant or breastfeeding. - known history of sars-cov-2 infection. - prior administration of an investigational coronavirus (sars-cov, middle east respiratory syndrome [mers]-cov) vaccine or current/planned simultaneous participation in another interventional study to prevent or treat covid-19. - demonstrated inability to comply with the study procedures. - an immediate family member or household member of this study's personnel. - history of anaphylaxis, urticaria, or other significant adverse reaction requiring medical intervention after receipt of a vaccine. - bleeding disorder considered a contraindication to intramuscular injection or phlebotomy. - has received or plans to receive a vaccine within 28 days prior to the first dose (day 1) or plans to receive a non-study vaccine within 28 days prior to or after any dose of investigational product (except for seasonal influenza vaccine). - has participated in an interventional clinical study within 28 days prior to the day of enrollment. - immunosuppressive or immunodeficient state, including human immunodeficiency virus (hiv) infection, asplenia, and recurrent severe infections. - has received systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to screening (for corticosteroids ≥20 milligram (mg)/day of prednisone equivalent). topical tacrolimus is allowed if not used within 14 days prior to screening. - has received systemic immunoglobulins or blood products within 3 months prior to the day of screening. - has donated ≥450 milliliters (ml) of blood products within 28 days prior to screening.