Study to Evaluate the Safety, Tolerability, and Immunogenicity of an RNA Vaccine Candidate Against COVID-19 in Healthy Japanese Adults

This is a Phase 1/2, randomized, placebo-controlled, and observer-blind study in healthy Japanese adults.

The study will evaluate the safety, tolerability, and immunogenicity of the SARS-CoV-2 RNA vaccine candidate against COVID-19:

* As 2 doses, separated by 21 days
* At a single dose level
* In adults 20 to 85 years of age

From protocol amendment 3, this study is transitioned from a clinical trial to a postmarketing study (Phase 4) according to the Japanese regulation, because BNT162b2 was approved by the Ministry of Health, Labour and Welfare on 14 February 2021.

Eligibility Criteria:
Inclusion Criteria:

* Japanese male or female participants between the ages of 20 and 85 years, inclusive, at randomization.
* 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.
* Capable of giving personal signed informed consent.

Exclusion Criteria:

* 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.