Inclusion Criteria:  Participant is willing and able to give written informed consent to participate in the study Age 18 years of age or older in good health or with mild or moderate stable co-morbidities at the time of enrolment Able and willing to complete all the scheduled study procedures during the whole study follow-up period If female of child-bearing potential and heterosexually active, has practiced adequate contraception for 30 days prior to injection, has a negative pregnancy test on the day of injection, and has agreed to continue adequate contraception until 3 months after the final dose of study vaccine (Please refer to the definition section for a description of child-bearing potential and adequate contraception) MOSAIC-1 Vaccine-exposed subgroups: have received or are booked to receive the first dose of an authorized COVID-19 vaccine in the 55 days prior to Visit 1 (documentation of receipt required) MOSAIC -1 Vaccine naïve subgroups: have not received an authorized COVID-19 vaccine at any time MOSAIC-2 participants have received two doses of COVID-19 vaccines authorized in Canada ≥6 months prior to study vaccine administration (documentation of receipt required)  Exclusion Criteria:  Inability or unwillingness of participant or legally acceptable representative to give written informed consent Any confirmed or suspected immunosuppressive or immunodeficient state; asplenia, or immunosuppressant medication within the past 6 months except short term oral steroids (≤14 days duration) or topical steroids Current diagnosis or treatment for cancer (except basal cell carcinoma of the skin) Administration of immunoglobulins and/or any blood products within 3 months preceding the first dose of study vaccine and for one month after the last dose of study vaccine Allergy to any study vaccine or any active substance in a study vaccine Bleeding disorder or history of significant bleeding following IM injections or venipuncture Continuous use of anticoagulants A history of anaphylaxis to a previous vaccine Pregnancy or intent to become pregnant during the study or within 3 months of the last dose of study vaccine MOSAIC-1: History of laboratory-confirmed COVID-19 disease prior to enrolment by participant report Administration of a live virus vaccine within 4 weeks prior to study vaccine receipt.