Trial Inclusion/Exclusion Criteria

Inclusion/Exclusion Criterion
Other medical or psychiatric condition incl. recent (within past year) or active suicidal ideation/behavior/lab abnormality that may increase the risk of study participation
Known infection with human immunodeficiency virus (HIV), hepatitis C virus (HCV), or hepatitis B virus (HBV)
Phase 1 & 2 only: 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
Stages 1 and 2 only: Previous clinical or microbiological diagnosis of COVID-19
Previous clinical or microbiological diagnosis of COVID-19
Previous clinical (based on COVID-19 symptoms/signs alone if no SARS-CoV-2 NAAT result) or microbiological (based on COVID-19 symptoms/signs and positive SARS-CoV-2 NAAT result) diagnosis of COVID-19
Sentinel participants in Stage 1 only: Individuals at high risk for severe COVID-19
Sentinel participants in Stage 1 only: Individuals at high risk for severe COVID-19 (full details in protocol)
Phase 1 only: Individuals at high risk for severe COVID-19 (full details in protocol)
Sentinel participants in Stage 1 only: Individuals currently working in occupations with high risk of exposure to SARS-CoV-2 (eg, healthcare worker, emergency response personnel)
Phase 1 only: Individuals currently working in occupations with high risk of exposure to SARS-CoV-2 (eg, healthcare worker, emergency response personnel)
Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination
Individuals with a history of autoimmune disease or an active autoimmune disease requiring therapeutic intervention
Sentinel participants in Stage 1 only: Individuals with a history of autoimmune disease or an active autoimmune disease requiring therapeutic intervention
Phase 1 only: Individuals with a history of autoimmune disease or an active autoimmune disease requiring therapeutic intervention
Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection
Previous vaccination with any coronavirus vaccine
Individuals who receive immunosuppressive therapy, such as cytotoxic agents or systemic corticosteroids. Inhaled/nebulized, Intra-articular, intrabursal, or topical corticosteroids are permitted
Subjects who receive immunosuppressive therapy, such as cytotoxic agents or systemic corticosteroids
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
Sentinel participants in Stage 1 only: Positive serological test for SARS-CoV-2 IgM and/or IgG antibodies at the screening visit
Phase 1 only: Positive serological test for SARS-CoV-2 IgM and/or IgG antibodies at the screening visit
Sentinel participants in Stage 1 only: Screening hematology/blood chemistry lab >=Grade 1 abnormality. Except Bilirubin, other stable Grade1 abnormalities may be considered eligible by Investigator
Phase 1 only: Screening hematology/blood chemistry lab >=Grade 1 abnormality. Except Bilirubin, other stable Grade1 abnormalities may be considered eligible by Investigator
Sentinel participants in Stage 1 only: Positive test for HIV, hepatitis B surface antigen (HBsAg), hepatitis B core antibodies (HBc Abs), or hepatitis C virus antibodies (HCV Abs) at screening visit
Phase 1 only: Positive test for HIV, hepatitis B surface antigen (HBsAg), hepatitis B core antibodies (HBc Abs), or hepatitis C virus antibodies (HCV Abs) at screening visit
Sentinel participants in Stage 1 only: SARS-CoV-2 NAAT-positive nasal swab within 24 hours before receipt of study intervention
Phase 1 only: SARS-CoV-2 NAAT-positive nasal swab within 24 hours before receipt of study intervention
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
Investigator site staff or Pfizer/BioNTech employees directly involved in the conduct of the study, site staff otherwise supervised by the investigator, and their respective family members
Sentinel participants in Stage 1 only: Regular receipt of inhaled/nebulized corticosteroids
Phase 1 only: Regular receipt of inhaled/nebulized corticosteroids
Male or female participants between the ages of 18 and 55 years, inclusive, 65 and 85 years, inclusive, or 18 and 85 years, inclusive, at randomization (dependent upon study stage)
Male or female participants between the ages of 18 and 55 years, inclusive, 65 and 85 years, inclusive, or 18 and 85 years, inclusive, at randomization (dependent upon study phase)
Male or female participants between the ages of 18 and 55 years, inclusive, and 65 and 85 years, inclusive (Phase 1), or >= 16 years (Phase 2/3), at randomization
Male or female participants between 18 and 55 years inclusive and 65 and 85 years inclusive (Phase 1) or >= 12 years (Phase 2/3) at randomization. Participants <18 years cannot be enrolled in EU
Participants who are willing and able to comply with all scheduled visits, vaccination plan, laboratory tests, lifestyle considerations, and other study procedures
Healthy participants who are determined by medical history, physical examination, and clinical judgment of the investigator to be eligible for inclusion in the study
Healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study
Healthy participants, determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for the study. Specific criteria apply for HIV/HCV/HBV
Capable of giving personal signed informed consent, which includes compliance with the requirements and restrictions listed in the ICD and in this protocol
Capable of giving personal signed informed consent/have parent/legal guardian capable of giving signed informed consent, which includes compliance with requirements, restrictions in ICD and protocol
Participants who, in the judgment of the investigator, are at risk for acquiring COVID-19
Phase 2/3 only: Participants who, in the judgment of the investigator, are at higher risk for acquiring COVID-19