Surveillance for Multisystem Inflammatory Syndrome in US Children Aged 5-11 Years Who Received Pfizer-BioNTech...

Area of Science:

• Pediatric infectious diseases
• Vaccine safety and immunology
• Public health surveillance

Background:

• Multisystem inflammatory syndrome in children (MIS-C) is a serious complication linked to SARS-CoV-2 infection.
• Monitoring MIS-C after COVID-19 vaccination is crucial for vaccine safety in pediatric populations.
• The Pfizer-BioNTech COVID-19 vaccine was authorized for children aged 5-11 years in October 2021.

Purpose of the Study:

• To assess the incidence of MIS-C in children aged 5-11 years following COVID-19 vaccination.
• To determine if MIS-C cases post-vaccination were associated with SARS-CoV-2 infection.
• To evaluate the safety of the Pfizer-BioNTech COVID-19 vaccine in young children regarding MIS-C.

Main Methods:

• Utilized passive surveillance systems to identify MIS-C cases within 90 days post-COVID-19 vaccination.
• Analyzed data from approximately 7 million vaccinated children aged 5-11 years.
• Distinguished MIS-C cases based on laboratory evidence of past or recent SARS-CoV-2 infection.

Main Results:

• Identified 58 children with MIS-C and evidence of SARS-CoV-2 infection post-vaccination.
• Identified 4 children with MIS-C but without evidence of SARS-CoV-2 infection post-vaccination.
• The incidence of MIS-C without SARS-CoV-2 infection evidence was rare (<1 per million vaccinated children) during high community transmission.

Conclusions:

• MIS-C following COVID-19 vaccination in children aged 5-11 years is rare, particularly in those without SARS-CoV-2 infection.
• The findings support the safety profile of the Pfizer-BioNTech COVID-19 vaccine in young children.
• Continued surveillance is important for monitoring vaccine safety and rare adverse events like MIS-C.