BACKGROUND AND PURPOSE:

• Walter et al. (NEJM, 2021) report on the safety and efficacy outcomes of a phase 2-3 trials of BNT162b2 (Pfizer) COVID-19 vaccine in children ages 5 to 11

METHODS:

• Phase 1 dose-finding study, and ongoing phase 2 to 3 randomized trial
• Participants
  • Children 6 months to 11 years of age | Data presented for children ages 5 to 11 years old
• Intervention
  • Phase 1
    • 10 μg, 20 μg, or 30 μg of BNT162b2 vaccine
  • Phase 2 to 3
    • Two doses of vaccine administered 21 days apart
      • Dose level identified during the open-label phase 1 study
    • Placebo
• Primary outcomes
  • Immune response 1 month after second dose
  • Vaccine efficacy against COVID-19 ≥7 days after second dose

RESULTS:

• Phase 1 study: 48 children
  • A dose level of 10 μg was selected based on reactogenicity and immunogenicity
• Phase 2 to 3 trial: 2268 children
  • Vaccine: 1517 children | Placebo: 751 children
  • Median follow-up up was 2.3 months at data cutoff
• Safety
  • The vaccine had a favorable safety profile in this age group
    • There were no vaccine-related serious adverse events
• Immunogenicity
  • Geometric mean ratio of SARS-CoV-2 neutralizing titers one month after second dose
    • 5- to 11-year-olds compared to 16- to 25-year-olds
    • 1.04 (95% CI, 0.93 to 1.18)
  • This ratio met the prespecified immunogenicity success criterion
• Efficacy against COVID-19
  • Incidence of COVID-19 onset ≥7 days after the second dose
    • Vaccine group: 3 individuals
    • Placebo group: 16 individuals
  • Vaccine efficacy: 90.7% (95% CI, 67.7 to 98.3)

CONCLUSION:

• The Pfizer vaccination regimen in children ages 5 to 11 was set at two 10 μg shots 21 days apart based on reactogenicity and immunogenicity data in this age group
• This vaccination regimen was safe, and immunogenicity was comparable to 16 to 25 year cohort
• Vaccine efficacy against COVID-19 for children aged 5 to 11 was 90.7%
• The authors state

The data reported herein support vaccination of 5-to-11-year-old children with two 10-μg doses of the BNT162b2 vaccine

Evaluation of BNT162b2 in younger children is ongoing

Learn More – Primary Sources:

Evaluation of the BNT162b2 Covid-19 Vaccine in Children 5 to 11 Years of Age

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