Top 5 Takeaways

  1. Widespread Vaccine Safety in Young Children: Among children aged 6 months–5 years, COVID-19 mRNA vaccines (Pfizer-BioNTech and Moderna) have shown a safety profile with primarily mild to moderate local and systemic reactions.
  2. Low Incidence of Serious Adverse Events: Serious adverse events are rare, with a majority of reported effects being non-serious, including irritability or crying, sleepiness, and fever.
  3. VAERS and v-safe Reporting: VAERS received 1,017 reports of adverse events, 98.1% of which were nonserious. V-safe enrolled 23,266 children, with systemic reactions more common in children aged 6 months–2 years.
  4. No Myocarditis Reports: Myocarditis, a rare adverse event linked to mRNA COVID-19 vaccines, was not reported in this age group during the study period.
  5. Public Health Implications: These findings support the ongoing recommendation for COVID-19 vaccination in children aged ≥6 months, with an emphasis on the rarity of serious adverse events.

Original Article Author and Citation

Corresponding Author

Anne M. Hause,

Suggested Citation

Hause AM, Marquez P, Zhang B, et al. COVID-19 mRNA Vaccine Safety Among Children Aged 6 Months–5 Years — United States, June 18, 2022–August 21, 2022. MMWR Morb Mortal Wkly Rep 2022;71:1115–1120. DOI:


This report evaluates the safety of the Pfizer-BioNTech and Moderna COVID-19 vaccines in children aged 6 months–5 years in the United States. Approximately one million doses were administered to this age group from June to August 2022. The report analyzes data from the Vaccine Adverse Event Reporting System (VAERS) and the v-safe surveillance system.


The study reviewed adverse events and health impacts reported to v-safe and VAERS following vaccination with Pfizer-BioNTech and Moderna vaccines. These systems collect data on local and systemic reactions, severity, and any health impacts post-vaccination.


The report highlights that most vaccine-related adverse events in children were mild to moderate, such as irritability or crying, sleepiness, and fever. Serious adverse events were extremely rare, and no cases of myocarditis were reported.


The findings suggest that the COVID-19 mRNA vaccines are safe for young children, with most reactions being mild and serious adverse events being rare. This aligns with preauthorization clinical trial data and supports the continued vaccination of children in this age group.

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