Effectiveness of BNT162b2 Vaccine against Omicron in Children 5 to 11 Years of Age

N Engl J Med. 2022 Aug 11;387(6):525-532. doi: 10.1056/NEJMoa2203209. Epub 2022 Jul 20.


Background: Since it was first identified in early November 2021, the B.1.1.529 (omicron) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread quickly and replaced the B.1.617.2 (delta) variant as the dominant variant in many countries. Data on the real-world effectiveness of vaccines against the omicron variant in children are lacking.

Methods: In a study conducted from January 21, 2022, through April 8, 2022, when the omicron variant was spreading rapidly, we analyzed data on children in Singapore who were 5 to 11 years of age. We assessed the incidences of all reported SARS-CoV-2 infections (confirmed on polymerase-chain-reaction [PCR] assay, rapid antigen testing, or both), SARS-CoV-2 infections confirmed on PCR assay, and coronavirus disease 2019 (Covid-19)-related hospitalizations among unvaccinated, partially vaccinated (≥1 day after the first dose of vaccine and up to 6 days after the second dose), and fully vaccinated children (≥7 days after the second dose). Poisson regression was used to estimate vaccine effectiveness from the incidence rate ratio of outcomes.

Results: A total of 255,936 children were included in the analysis. Among unvaccinated children, the crude incidence rates of all reported SARS-CoV-2 infections, PCR-confirmed SARS-CoV-2 infections, and Covid-19-related hospitalizations were 3303.5, 473.8, and 30.0 per 1 million person-days, respectively. Among partially vaccinated children, vaccine effectiveness was 13.6% (95% confidence interval [CI], 11.7 to 15.5) against all SARS-CoV-2 infections, 24.3% (95% CI, 19.5 to 28.9) against PCR-confirmed SARS-CoV-2 infection, and 42.3% (95% CI, 24.9 to 55.7) against Covid-19-related hospitalization; in fully vaccinated children, vaccine effectiveness was 36.8% (95% CI, 35.3 to 38.2), 65.3% (95% CI, 62.0 to 68.3), and 82.7% (95% CI, 74.8 to 88.2), respectively.

Conclusions: During a period when the omicron variant was predominant, BNT162b2 vaccination reduced the risks of SARS-CoV-2 infection and Covid-19-related hospitalization among children 5 to 11 years of age.

MeSH terms

  • BNT162 Vaccine* / pharmacology
  • BNT162 Vaccine* / therapeutic use
  • COVID-19* / epidemiology
  • COVID-19* / prevention & control
  • COVID-19* / virology
  • Child
  • Child, Preschool
  • Hospitalization / statistics & numerical data
  • Humans
  • SARS-CoV-2* / drug effects
  • SARS-CoV-2* / genetics
  • Singapore / epidemiology
  • Vaccine Efficacy* / statistics & numerical data
  • Viral Vaccines / pharmacology
  • Viral Vaccines / therapeutic use


  • Viral Vaccines
  • BNT162 Vaccine

Supplementary concepts

  • SARS-CoV-2 variants