Journal article
Safety and Immunogenicity of a Fourth Dose of Omicron-BA.1-Adapted BNT162b2 COVID-19 Vaccines in Adults 18‒55 Years Old
Clinical infectious diseases
01/21/2026
DOI: 10.1093/cid/ciag026
PMID: 41560517
Abstract
Emergence of SARS-CoV-2 sublineages warrants the use of sequence-adapted vaccines to provide protection against COVID-19.
In this phase 3 trial, adults 18‒55 years old who had previously received three 30-μg doses of BNT162b2 vaccine were randomized to receive a 60- or 30-μg dose of bivalent Omicron BA.1‒adapted BNT162b2 comprising equal amounts of ancestral and monovalent messenger RNA BA.1 (bivalent BA.1) or a 60-μg dose of monovalent Omicron BA.1‒adapted BNT162b2 (monovalent BA.1). Safety (local reactions, systemic events, adverse events [AEs], and serious AEs) was the primary objective. Exploratory analyses assessed immune responses against Omicron-BA.1, BA.4, and BA.5 subvariants and ancestral strain.
Among the 1054 randomized participants who received monovalent BA.1 or bivalent BA.1, frequencies of local reactions, systemic events, and AEs were slightly higher with 60-µg monovalent BA.1 than either bivalent BA.1 dose level. One month after vaccination, bivalent BA.1 (30 μg and 60 μg) and monovalent BA.1 (60 μg) induced substantial neutralizing responses against Omicron BA.1 (50% neutralizing titer geometric mean fold rises [GMFRs]: 15.4 [95% CI 12.4-19.2], 17.1 [13.7-21.4], and 24.6 [19.3-31.4], respectively) and ancestral strain (GMFRs: 6.2 [5.1-7.6], 7.3 [6.0-8.9], and 7.0 [5.7-8.7], respectively). In a smaller (n=30/treatment arm) sentinel cohort, all study vaccines modestly neutralized Omicron BA.4 and BA.5.
Bivalent and monovalent BA.1‒adapted vaccines had a safety profile similar to original BNT162b2 30 μg and induced substantial neutralizing responses against Omicron BA.1 and ancestral strains.NCT04955626.
Details
- Title: Subtitle
- Safety and Immunogenicity of a Fourth Dose of Omicron-BA.1-Adapted BNT162b2 COVID-19 Vaccines in Adults 18‒55 Years Old
- Creators
- Patricia Winokur - University of IowaOyeniyi Diya - PfizerDavid Fitz-Patrick - East–West CenterMichael Dever - Orlando Clinical Research CenterJuleen Gayed - PfizerStephen Lockhart - PfizerXia Xu - PfizerYing Zhang - PfizerVishva Bangad - PfizerL Tyler Wadsworth - Sundance Clinical ResearchKevin Cannon - University of North Carolina WilmingtonJose F Cardona - University of Science and Technology ChittagongLisa Usdan - CNS HealthcareJohn Ginis - PfizerFederico J Mensa - BioNTechJing Zou - The University of Texas Medical Branch at GalvestonXuping Xie - The University of Texas Medical Branch at GalvestonClaire Lu - PfizerSandra Buitrago - PfizerIngrid L Scully - PfizerDavid Cooper - PfizerKenneth Koury - PfizerKathrin U Jansen - PfizerӦzlem Türeci - BioNTechUğur Şahin - BioNTechKena A Swanson - PfizerWilliam C Gruber - PfizerNicholas Kitchin - Pfizer
- Resource Type
- Journal article
- Publication Details
- Clinical infectious diseases
- DOI
- 10.1093/cid/ciag026
- PMID
- 41560517
- NLM abbreviation
- Clin Infect Dis
- ISSN
- 1058-4838
- eISSN
- 1537-6591
- Publisher
- Oxford University Press
- Language
- English
- Electronic publication date
- 01/21/2026
- Academic Unit
- Infectious Diseases; Medicine Administration; Internal Medicine
- Record Identifier
- 9985130057702771
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