mRNA COVID-19 vaccine safety among children and adolescents: a Canadian National Vaccine Safety Network cohort studyResearch in context

• Main Authors: Phyumar Soe (Author), Otto G. Vanderkooi (Author), Manish Sadarangani (Author), Monika Naus (Author), Matthew P. Muller (Author), James D. Kellner (Author), Karina A. Top (Author), Hubert Wong (Author), Jennifer E. Isenor (Author), Kimberly Marty (Author), Hennady P. Shulha (Author), Gaston De Serres (Author), Louis Valiquette (Author), Allison McGeer (Author), Julie A. Bettinger (Author)
• Format: Book
• Published: Elsevier, 2024-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Summary: Background: The Canadian National Vaccine Safety Network conducted active safety surveillance for COVID-19 vaccines. This study aimed to characterize the short-to-medium term safety of mRNA COVID-19 vaccines across the pediatric age spectrum. Methods: In this cohort study, vaccinated and unvaccinated children and adolescents aged 6 months to 19 years from eight Canadian provinces and territories were invited to participate. The outcome was a health event preventing daily activities, resulting in school absenteeism, or requiring medical consultation. Age-stratified multivariable regression models were used to examine health events associated with first and second doses of mRNA COVID-19 vaccines across different age groups: children under 5, children aged 5-11 years and adolescents aged 12-19 years. Findings: From January 2021 through February 2023, a total of 259,361 individuals from the dose one survey, 131,032 from the dose 2 survey, and 1179 from the control survey were included. In the week following dose two, vaccinated adolescents showed a higher proportion of health events [794 (4.6%) of 17,218 BNT162b2 recipients, 98 (8.5%) of 1153 mRNA-1273 recipients, 49 of (10.6%) of 464 heterologous schedule recipients] than unvaccinated adolescents [9 (3.7%) of 242 controls], but most events were self-limited and resolved within 7 days. No significant differences in proportion of health events following mRNA COVID-19 vaccines were observed between vaccinated and unvaccinated groups among adolescents after dose 1, or among children under 5 or those aged 5-11 years after any dose. Reported myocarditis/pericarditis cases within 0-28 days peaked among male adolescents following dose 2, in three of (0.037%) 8088 homologous BNT162b2 recipients, and two of (0.529%) 378 homologous mRNA-1273 recipients. Interpretation: Our findings suggest that reported health events, including myocarditis/pericarditis, vary by pediatric age group. Vaccinated adolescents reported health events more frequently following the second mRNA COVID-19 vaccine dose, while younger age groups did not report events more frequently than their unvaccinated counterparts. Funding: Canadian Immunization Research Network, Canadian Institutes of Health Research; Public Health Agency of Canada; COVID-19 Immunity Task Force.

Item Description

2667-193X
10.1016/j.lana.2024.100949