* other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. * known infection with human immunodeficiency virus (hiv), hepatitis c virus (hcv), or hepatitis b virus (hbv). * history of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s). * receipt of medications intended to prevent covid-19. * previous confirmed diagnosis of covid-19. * immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination. * bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection. * women who are pregnant or breastfeeding. * previous vaccination with any coronavirus vaccine. * individuals who receive treatment with immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids, eg, for cancer or an autoimmune disease, or planned receipt throughout the study. * receipt of blood/plasma products or immunoglobulin, from 60 days before study intervention administration or planned receipt throughout the study. * participation in other studies involving study intervention within 28 days prior to study entry and/or during study participation. * previous participation in other studies involving study intervention containing lipid nanoparticles. * subset only: any screening hematology and/or blood chemistry laboratory value that meets the definition of a ≥ grade 1 abnormality. * investigator site staff or pfizer employees directly involved in the conduct of the study, site staff otherwise supervised by the investigator, and their respective family members.

* other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. * known infection with human immunodeficiency virus (hiv), hepatitis c virus (hcv), or hepatitis b virus (hbv). * history of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s). * receipt of medications intended to prevent covid-19. * previous confirmed diagnosis of covid-19. * immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination. * bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection. * women who are pregnant or breastfeeding. * previous vaccination with any coronavirus vaccine. * individuals who receive treatment with immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids, eg, for cancer or an autoimmune disease, or planned receipt throughout the study. * receipt of blood/plasma products or immunoglobulin, from 60 days before study intervention administration or planned receipt throughout the study. * participation in other studies involving study intervention within 28 days prior to study entry and/or during study participation. * previous participation in other studies involving study intervention containing lipid nanoparticles. * subset only: any screening hematology and/or blood chemistry laboratory value that meets the definition of a ≥ grade 1 abnormality. * investigator site staff or pfizer employees directly involved in the conduct of the study, site staff otherwise supervised by the investigator, and their respective family members.

- other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. - known infection with human immunodeficiency virus (hiv), hepatitis c virus (hcv), or hepatitis b virus (hbv). - history of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s). - receipt of medications intended to prevent covid-19. - previous confirmed diagnosis of covid-19. - immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination. - bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection. - women who are pregnant or breastfeeding. - previous vaccination with any coronavirus vaccine. - individuals who receive treatment with immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids, eg, for cancer or an autoimmune disease, or planned receipt throughout the study. - receipt of blood/plasma products or immunoglobulin, from 60 days before study intervention administration or planned receipt throughout the study. - participation in other studies involving study intervention within 28 days prior to study entry and/or during study participation. - previous participation in other studies involving study intervention containing lipid nanoparticles. - subset only: any screening hematology and/or blood chemistry laboratory value that meets the definition of a ≥ grade 1 abnormality. - investigator site staff or pfizer employees directly involved in the conduct of the study, site staff otherwise supervised by the investigator, and their respective family members.

- other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. - known infection with human immunodeficiency virus (hiv), hepatitis c virus (hcv), or hepatitis b virus (hbv). - history of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s). - receipt of medications intended to prevent covid-19. - previous confirmed diagnosis of covid-19. - immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination. - bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection. - women who are pregnant or breastfeeding. - previous vaccination with any coronavirus vaccine. - individuals who receive treatment with immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids, eg, for cancer or an autoimmune disease, or planned receipt throughout the study. - receipt of blood/plasma products or immunoglobulin, from 60 days before study intervention administration or planned receipt throughout the study. - participation in other studies involving study intervention within 28 days prior to study entry and/or during study participation. - previous participation in other studies involving study intervention containing lipid nanoparticles. - subset only: any screening hematology and/or blood chemistry laboratory value that meets the definition of a ≥ grade 1 abnormality. - investigator site staff or pfizer employees directly involved in the conduct of the study, site staff otherwise supervised by the investigator, and their respective family members.