PaedVacCOVID - safety of the BNT162b2 vaccine against the SARS-CoV-2 in children with and without comorbidities aged 5 to 11 years.

Background: Little is known about specific safety aspects in children with significant comorbidities receiving the mRNA vaccine BNT162b2, as approval studies did not address this population. This study's purpose is to evaluate safety and adverse events in these children compared to healthy children.

Methods: In this prospective, multicentre, industry-independent cohort study, caregivers whose children received BNT162b2 were asked to participate in an online questionnaire. Potential side effects were evaluated in ten organ related categories. Frequency of symptoms was compared in both cohorts by bivariate analysis.

Results: From a total of 1,294 responses to the questionnaire, 793 data sets were included into the analysis (179 children with comorbidities and 614 healthy children). Responses were given at a median of 17 days after vaccination. Overall, safety of BNT162b2 was high in both cohorts. Psychological (OR: 3.56, [95% CI: 1.461 to 8.629]), pulmonary (OR: 7.14, [95% CI: 2.039 to 21.48]), gastrointestinal (OR: 2.35, [95% CI: 1.231 to 4.665]), neurological (OR: 1.74, [95% CI: 1.078 to 2.796]) and dermatological (OR: 2.28, [95% CI: 1.220 to 4.172]) side effects were increased in children with comorbidities over healthy controls.

Conclusion: The higher rate of reported post-vaccination symptoms could either be due to a higher susceptibility for symptomatic effects following immune stimulation, or due to a trained awareness to health-related symptoms. The data emphasizes the importance to evaluate safety of the new mRNA COVID-19 vaccines not only in healthy children but also in children with comorbidities. To perform such evaluation should be made mandatory for pharmaceutical enterprises.