A Phase 3 Study to Evaluate the Safety, Tolerability, and Immunogenicity of Multiple Production Lots and Dose Levels of BNT162b2 RNA-Based COVID-19 Vaccines Against COVID-19 in Healthy Participants

This is a Phase 3, randomized, observer-blind study in healthy individuals.

The primary study will evaluate the safety, tolerability, and immunogenicity of the SARS-CoV-2 RNA vaccine candidate (BNT162b2):

* As a 30-microgram dose, administered from 1 of 4 manufacturing lots (batches)
* As a 20-microgram dose, administered from 1 of the manufacturing lots
* As a 2-dose (separated by 21 days) schedule
* In people 12 through 50 years of age

The booster study will evaluate the safety, tolerability, and immunogenicity of 2 SARS-CoV-2 RNA vaccine candidates (BNT162b2 and BNT162b2.B.1.351):

* Each as a 30-microgram dose
* Each as a 1-dose booster vaccine, administered approximately 3 months after Dose 2
* In people 18 through 50 years of age


Eligibility Criteria:
Inclusion Criteria:

* Primary study: Male or female participants between the ages of 12 and 50 years, inclusive, at randomization.
* Booster study: Male or female participants between the ages of 18 and 50 years, inclusive, at rerandomization.
* Participants who are willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures.
* 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.
* Capable of giving personal signed informed consent/have parent(s)/legal guardian capable of giving 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 HIV, HCV, or HBV.
* History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention.
* Previous clinical (based on COVID-19 symptoms/signs alone, if a SARS-CoV-2 NAAT result was not available) or microbiological (based on COVID-19 symptoms/signs and a positive SARS-CoV-2 NAAT result) 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.
* Primary study: Previous vaccination with any coronavirus vaccine.
* Booster study: Previous vaccination with any coronavirus vaccine outside of this study.
* Receipt of medications intended to prevent COVID-19.
* Individuals who receive treatment with radiotherapy or 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.
* 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.

Additional Exclusion Criteria for the Booster study:

* Current febrile illness (body temperature ≥100.4°F \[≥38.0°C\]) or other acute illness within 48 hours before study intervention administration.
* Receipt of any seasonal or pandemic influenza vaccine within 14 days, or any other nonstudy vaccine within 28 days, before or after study intervention administration.
* Receipt of short-term (\<14 days) systemic corticosteroids. Inhaled/nebulized, intra-articular, intrabursal, or topical (skin or eyes) corticosteroids are permitted.