Table 4

Duration of protection from COVID-19 vaccine primary series against infection and hospitalisation in children and adolescents

Vaccine typeVaccine efficacy and effectiveness
<12 years12–17 years
Pfizer-BioNTech
(mRNA)
Omicron (BA.1) effectiveness against
  • Symptomatic infection in Singapore (5–11 years)

    • 7–14 days post-vaccination: 49%

    • 15–29 days post-vaccination: 38%

    • 30–59 days post-vaccination: 29%

    • ≥60 days post-vaccination: 26%129

  • Hospitalisation in Singapore (5–11 years)

    • 83% without evidence of waning up to 2 months129

  • Hospitalisation in the USA (5–11 years)

    • Median 34 days post-vaccination: 68%130

Delta effectiveness against
  • Hospitalisation in the USA (12–18 years)

    • 2–22 weeks post-vaccination: 93%

    • 23–44 weeks post-vaccination: 92%130


Delta or Omicron effectiveness against
  • Hospitalisation in the USA (12–15 years)

    • <5 months post-vaccination: 92%

    • ≥5 months post-vaccination: 73%117

  • Hospitalisation in the USA (16–17 years)

    • <5 months post-vaccination: 94%

    • ≥5 months post-vaccination: 88%117


Omicron effectiveness against
  • Symptomatic infection in the UK (12–17 years)

    • ≥70 days post-vaccination: 23%131

  • Hospitalisation in the USA (12–18 years)

    • 2–22 weeks post-vaccination: 43%

    • 23–44 weeks post-vaccination: 38%130