Year: 2026
Type: article
Abstract: BACKGROUND: Sex differences exist not only in the efficacy but also in adverse event rates of many vaccines. Here we compared the sex differences in the tolerability of BNT162b2 in children younger than 18 years in Germany. METHODS: A post-hoc analysis of retrospectively collected tolerability data, collected through an authentication-based survey of legal guardians of children vaccinated with BNT162b2 under the age of 18 years (CoVacU18-study). Primary outcome was the frequency of the four most common post-vaccination symptom categories (local, general, musculoskeletal symptoms, fever) reported after the 1st-4th doses. Data were analyzed according to sex in bivariate analyses and regression models adjusting for age, weight, and dosage. Interactions between sex and age group effects on post-vaccination symptoms were assessed. An active-comparator analysis was applied to compare post-vaccination symptoms after BNT162b2 versus non-SARS-CoV-2 vaccines. RESULTS: Three thousand two hundred twenty-eight participants (median age 5.7 years, male 49.6%). In logistic regression, female sex was associated with higher odds of local symptoms (OR = 1.28 [95% CI: 1.17-1.40], p < 0.05), general symptoms (OR = 1.27 [1.13-1.44], p < 0.05), and musculoskeletal symptoms (OR = 1.27 [1.03-1.56], p < 0.05). Interactions between sex and age groups existed for post-vaccination local symptoms. Following non-BNT162b2 childhood vaccinations, female sex was not associated with odds of any post-vaccination symptoms. No relevant interaction existed between vaccine types (BNT162b2 vs non-BNT162b2) and sex for the association with post-vaccination symptoms. CONCLUSION: Sex differences exist in post-vaccination symptoms after BNT162b2 administration in young children and adolescents. These are of importance for the conception of approval studies, for post-vaccination monitoring and for future vaccination strategies.
Institutions: University of Bern, University of Zurich, Karolinska Institutet, Witten/Herdecke University, Asklepios Klinik Sankt Augustin, Asklepios, University Hospital Carl Gustav Carus, Technische Universität Dresden, University Hospital of Bern, University Hospital Schleswig-Holstein, Justus-Liebig-Universität Gießen, Helios Universitätsklinikum Wuppertal, German Center for Lung Research, Universities of Giessen and Marburg Lung Center, Cardio-Pulmonary Institute
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,590
Funder: Universität Witten/Herdecke
OpenAlex ID: W7162468069