Bivalent Omicron BA.1-Adapted BNT162b2 Booster in Adults Older than 55 Years

Patricia Winokur, Juleen Gayed, David Fitz-Patrick, Stephen J. Thomas, Oyeniyi Diya, Stephen Lockhart, Xia Xu, Ying Zhang, Vishva Bangad, Howard I. Schwartz, Douglas Denham, Jose F. Cardona, Lisa Usdan, John Ginis, Federico J. Mensa, Jing Zou, Xuping Xie, Pei Yong Shi, Claire Lu, Sandra BuitragoIngrid L. Scully, David Cooper, Kenneth Koury, Kathrin U. Jansen, Özlem Türeci, Uǧur Şahin, Kena A. Swanson, William C. Gruber, Nicholas Kitchin

Research output: Contribution to journalArticlepeer-review

55 Scopus citations


Background: The emergence of immune-escape variants of severe acute respiratory syndrome coronavirus 2 warrants the use of sequence-adapted vaccines to provide protection against coronavirus disease 2019. Methods: In an ongoing phase 3 trial, adults older than 55 years who had previously received three 30-μg doses of the BNT162b2 vaccine were randomly assigned to receive 30 μg or 60 μg of BNT162b2, 30 μg or 60 μg of monovalent B.1.1.529 (omicron) BA.1-adapted BNT162b2 (monovalent BA.1), or 30 μg (15 μg of BNT162b2+15 μg of monovalent BA.1) or 60 μg (30 μg of BNT162b2+30 μg of monovalent BA.1) of BA.1-adapted BNT162b2 (bivalent BA.1). Primary objectives were to determine superiority (with respect to 50% neutralizing titer [NT50] against BA.1) and noninferiority (with respect to seroresponse) of the BA.1-adapted vaccines to BNT162b2 (30 μg). A secondary objective was to determine noninferiority of bivalent BA.1 to BNT162b2 (30 μg) with respect to neutralizing activity against the ancestral strain. Exploratory analyses assessed immune responses against omicron BA.4, BA.5, and BA.2.75 subvariants. Results: A total of 1846 participants underwent randomization. At 1 month after vaccination, bivalent BA.1 (30 μg and 60 μg) and monovalent BA.1 (60 μg) showed neutralizing activity against BA.1 superior to that of BNT162b2 (30 μg), with NT50 geometric mean ratios (GMRs) of 1.56 (95% confidence interval [CI], 1.17 to 2.08), 1.97 (95% CI, 1.45 to 2.68), and 3.15 (95% CI, 2.38 to 4.16), respectively. Bivalent BA.1 (both doses) and monovalent BA.1 (60 μg) were also noninferior to BNT162b2 (30 μg) with respect to seroresponse against BA.1; between-group differences ranged from 10.9 to 29.1 percentage points. Bivalent BA.1 (either dose) was noninferior to BNT162b2 (30 μg) with respect to neutralizing activity against the ancestral strain, with NT50 GMRs of 0.99 (95% CI, 0.82 to 1.20) and 1.30 (95% CI, 1.07 to 1.58), respectively. BA.4-BA.5 and BA.2.75 neutralizing titers were numerically higher with 30-μg bivalent BA.1 than with 30-μg BNT162b2. The safety profile of either dose of monovalent or bivalent BA.1 was similar to that of BNT162b2 (30 μg). Adverse events were more common in the 30-μg monovalent-BA.1 (8.5%) and 60-μg bivalent-BA.1 (10.4%) groups than in the other groups (3.6 to 6.6%). Conclusions: The candidate monovalent or bivalent omicron BA.1-adapted vaccines had a safety profile similar to that of BNT162b2 (30 μg), induced substantial neutralizing responses against ancestral and omicron BA.1 strains, and, to a lesser extent, neutralized BA.4, BA.5, and BA.2.75 strains.

Original languageEnglish (US)
Pages (from-to)214-227
Number of pages14
JournalNew England Journal of Medicine
Issue number3
StatePublished - 2023


  • Coronavirus
  • Infectious Disease
  • Vaccines
  • Viral Infections

ASJC Scopus subject areas

  • General Medicine


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