What is the evidence behind COVID-19 booster shots for pediatric patients?

Evidence Behind COVID-19 Booster Shots for Pediatric Patients

The Advisory Committee on Immunization Practices (ACIP) recommends that all children aged ≥5 years receive one bivalent mRNA booster dose ≥2 months after completion of any FDA-approved or FDA-authorized monovalent primary series or monovalent booster doses. 1

Current Recommendations and Evidence Base

Bivalent Booster Recommendations

• The CDC expanded recommendations in October 2022 to include bivalent booster doses for children aged ≥5 years 1
• These recommendations were based on:
  • Safety and immunogenicity data from monovalent boosters in pediatric populations
  • Data on bivalent boosters in adults
  • Evidence of waning vaccine effectiveness after primary series during the Omicron-predominant period

Immunogenicity Evidence

• For Moderna's monovalent booster in children:
  • Children aged 6-11 years showed 4.2-fold higher neutralization titers compared to young adults after primary series
  • Adolescents aged 12-17 years showed 5.1-fold higher neutralization titers 1
• Reactogenicity symptoms were similar to those observed in adults

Effectiveness and Public Health Impact

• Modeling data showed that broader booster coverage (similar to influenza vaccine coverage) would lead to:

  • 20% reduction in hospitalizations

  • 15% reduction in deaths compared to limiting boosters to adults ≥50 years 1

• Early administration of boosters (September vs. November 2022) was projected to prevent 137,000 more hospitalizations and 9,700 more deaths 1

Safety Considerations

Myocarditis Risk

• A rare risk for myocarditis and pericarditis has been identified after mRNA COVID-19 vaccination, primarily in adolescent and young adult males 1
• The risk after bivalent booster doses was not fully known at the time of recommendation
• However, data indicated that the risk after monovalent mRNA COVID-19 booster doses was similar to or lower than the risk after dose 2 of the primary series 1

General Safety Profile

• As of November 2022, no unexpected patterns of serious adverse events related to the vaccine were reported for mRNA COVID-19 bivalent booster doses 1
• The Pfizer-BioNTech COVID-19 vaccine demonstrated high efficacy (>90%) against COVID-19 in children aged 5-11 years 2

Clinical Considerations for Pediatric COVID-19 Vaccination

Special Populations

• Children with multisystem inflammatory syndrome (MIS-C) may benefit from vaccination to prevent recurrence
• MIS-C typically occurs 2-4 weeks after SARS-CoV-2 infection and can cause Kawasaki-like and toxic shock syndrome-like diseases 1

Risk-Benefit Assessment

• While children generally have lower risk of severe COVID-19 compared to adults, they can still develop serious consequences including MIS-C 3
• The American Academy of Pediatrics (AAP) states that COVID-19 vaccines are safe and effective in protecting against serious outcomes including post-acute sequelae of SARS-CoV-2 infection (PASC) and MIS-C 4

Implementation Challenges and Considerations

Equity Considerations

• ACIP examined data pertaining to equity in their recommendations, including:
  • Disproportionate incidence of COVID-19 illness, hospitalization, and death among racial and ethnic minority groups
  • Demographic characteristics of clinical trial populations compared to the U.S. population
  • Evidence of persistent inequity in receipt of primary series and booster doses 1

Practical Implementation

• Vaccine hesitancy among parents remains a significant challenge for pediatric COVID-19 vaccination 1
• Preventive measures like face masks, hand hygiene, and social distancing are less applicable in children than adults, highlighting the importance of vaccination 1

Conclusion

The evidence supports the use of COVID-19 booster shots in pediatric patients aged ≥5 years, with data showing favorable immunogenicity and an acceptable safety profile. While the absolute benefit may be lower than in adults due to children's generally lower risk of severe COVID-19, vaccination provides important protection against serious outcomes including MIS-C and contributes to community-level protection by reducing transmission.