A Study to Learn About New COVID-19 RNA Vaccine Candidates in COVID-19 Vaccine-Experienced Healthy Individuals

Study Summary

The purpose of this clinical trial is to learn about the safety, tolerability and immunogenicity of BNT162b RNA-based SARS-CoV-2 vaccine candidates in adults to prevent COVID-19. For all cohorts (groups of participants), this study is seeking participants who are healthy (who may have preexisting disease if it is stable); All participants will receive a single dose of the study vaccine at the first study clinic and will return to the study clinic at least 4 more times. At each clinic visit, a blood sample will be taken. The study is about 6 months long for each participant. The vaccine candidates in this study are investigational but are very similar to BNT162b2 (Comirnaty), a COVID-19 RNA vaccine approved for use in the US and in many countries. For Cohort 1, this study included participants who were: * 18 through 55 years of age * have received 1 booster dose of a US-authorized COVID-19 vaccine, with the last dose being 90 or more days before Visit 1 of this study. All participants in Cohort 1 will receive 1 of the 2 study vaccines at a 30 microgram dose: BNT162b5 Bivalent (WT/OMI BA.2) or BNT162b2 Bivalent (WT/OMI BA.1). For Cohort 2, this study included participants who were: * 12 years of age and older * have received 3 prior doses of 30 micrograms BNT162b2, with the last dose being 150 to 365 days before Visit 1 of this study. Participants 12 through 17 years of age will receive BNT162b2 Bivalent (WT/OMI BA.4/BA.5) 30 micrograms. Participants 18 years and older will receive BNT162b2 Bivalent (WT/OMI BA.4/BA.5) at either a 30 microgram or a 60 microgram dose. For Cohort 3, this study included participants who were: * 18 years of age and older * have received 3 prior doses of 30 micrograms BNT162b2, with the last dose being 150 to 365 days before Visit 1 of this study. * Participants will receive BNT162b2 Bivalent (WT/OMI BA.4/BA.5) 30 micrograms. For Cohort 4, this study is seeking participants who are: * 18 through 55 years of age * have received 3

Primary Outcome

Local reactions were recorded by participants in an electronic diary (e-diary). Local reactions included redness, swelling and pain at injection site. Redness and swelling were graded as mild: greater than (\>) 2.0 to 5.0 centimeter (cm), moderate: \>5.0 to 10.0 cm, severe: \>10.0 cm, grade 4 (potentially life threatening): necrosis or exfoliative dermatitis (redness) and necrosis (swelling). Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered w

Interventions

• BIOLOGICAL BNT162b5 Bivalent (WT/OMI BA.2)
• BIOLOGICAL BNT162b2 Bivalent (WT/OMI BA.1)
• BIOLOGICAL BNT162b2 Bivalent (WT/OMI BA.4/BA.5)
• BIOLOGICAL BNT162b5 Bivalent (Original/OMI BA.4/BA.5)
• BIOLOGICAL BNT162b6 Bivalent (Original/OMI BA.4/BA.5)