Top 5 Takeaways

1. High Vaccine Effectiveness: The Pfizer-BioNTech vaccine showed a 91% effectiveness against MIS-C in persons aged 12–18 years.
2. Critical Illness Prevention: All critically ill MIS-C patients requiring life support were unvaccinated.
3. Reinforcement of Vaccination: The findings support the recommendation for COVID-19 vaccination among eligible children to prevent MIS-C.
4. Study Design: The effectiveness was assessed using a test-negative case-control design among hospitalized patients.
5. Geographic and Temporal Scope: The study included 24 pediatric hospitals across 20 states during the Delta variant predominance period.

Original Article Author and Citation

Corresponding Author

Laura D. Zambrano, lzambrano@cdc.gov

Suggested Citation

Zambrano LD, Newhams MM, Olson SM, et al. Effectiveness of BNT162b2 (Pfizer-BioNTech) mRNA Vaccination Against Multisystem Inflammatory Syndrome in Children Among Persons Aged 12–18 Years — United States, July–December 2021. MMWR Morb Mortal Wkly Rep 2022;71:52–58. DOI: http://dx.doi.org/10.15585/mmwr.mm7102e1

Summary

This study assessed the effectiveness of the Pfizer-BioNTech COVID-19 vaccine in preventing multisystem inflammatory syndrome in children (MIS-C) among individuals aged 12–18 years. The vaccine demonstrated a 91% effectiveness rate. The study used a test-negative case-control design and included 24 pediatric hospitals across 20 states during the period of Delta variant predominance. The findings highlight the importance of vaccination in preventing severe complications related to COVID-19 in children.

Methods

The study employed a test-negative case-control design, involving hospitalized patients aged 12–18 years at 24 pediatric hospitals. MIS-C case-patients and two control groups (test-negative and syndrome-negative) were compared. Vaccination status was verified through state immunization systems, medical records, and other documentation. The effectiveness was calculated using multivariable logistic regression models adjusted for various demographic factors.

Discussion

The study found that the Pfizer-BioNTech vaccine is highly effective in preventing MIS-C among adolescents. Most MIS-C patients were unvaccinated, and no fully vaccinated patients required life support. The findings align with previous evidence showing high vaccine effectiveness against severe COVID-19 complications. However, the study had limitations, including the inability to assess effectiveness against specific variants and the short time frame of enrollment.

Conclusion

The Pfizer-BioNTech vaccine provides strong protection against MIS-C in adolescents, reinforcing the importance of vaccinating all eligible children. The study supports the ongoing recommendation for COVID-19 vaccination to prevent severe outcomes in children.

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