Maria Linn Olivia Östman

• Östman, Maria Linn Olivia; Størdal, Ketil; Tapia, German & Stene, Lars Christian Mørch (2026). Rotavirus vaccination and incidence of type 1 diabetes: a population-based natural experiment. Diabetologia. ISSN 0012-186X. doi: 10.1007/s00125-026-06832-0. Full text in Research Archive Show summary

  Aims/hypothesis Environmental factors, including infections, have been suspected to influence the risk of type 1 diabetes. Studies of rotavirus vaccine and risk of type 1 diabetes have shown conflicting results. We took advantage of the rapid and high uptake of the rotavirus vaccine among infants in Norway as a natural experiment to study the potential association between rotavirus vaccination and type 1 diabetes incidence in Norway. Methods In this cohort study, we followed all children born in Norway during 2007–2019 from 6 months to 5 years of age for type 1 diabetes. In an interrupted time series analysis, we compared type 1 diabetes incidence in children born before compared with after introduction of the rotavirus vaccination programme in September 2014. Results Of 740,744 included children, 846 were diagnosed with type 1 diabetes between 6 months and 5 years of age. Our primary interrupted time series analysis showed an increasing trend after implementation of the rotavirus vaccination programme (relative HR 1.11 [95% CI 1.03, 1.20]), which was not significant after excluding birth cohorts from 2013–2015 to avoid potential herd immunity effects (relative HR 1.05 [95% CI 0.93, 1.18]). In a secondary analysis comparing fully vaccinated with non-vaccinated children, the adjusted HR was 1.17 (95% CI 0.78, 1.77). Conclusions/Interpretation This study found no evidence for a reduced risk of type 1 diabetes after introduction of rotavirus vaccination in infancy.

• Östman, Maria Linn Olivia; Stene, Lars Christian Mørch; Tapia, German; Kivelä, Laura; Kurppa, Kalle & Størdal, Ketil (2025). Risk of Celiac Disease Before and After Nationwide Infant Rotavirus Vaccination: A Population-Based Study. Journal of Pediatrics. ISSN 0022-3476. 290. doi: 10.1016/j.jpeds.2025.114938. Full text in Research Archive Show summary

  Objective To study the association between rotavirus vaccination and risk of celiac disease, which remains debated. Study design We conducted a nationwide register-based study including 740 744 children born during 2007-2019 from the Norwegian Birth Registry individually linked to the Norwegian Patient Registry for celiac disease diagnosis. With follow-up until 5 years of age, 2795 were diagnosed with celiac disease. The main analysis was an interrupted time series analysis to assess break in trend of celiac disease incidence before compared with after vaccine introduction in September 2014. Furthermore, we linked the cohort to the Norwegian Immunization Register and compared the risk of celiac disease between fully vaccinated and nonvaccinated children. In sensitivity analyses, we excluded children born 1 year before to 1 year after vaccine introduction to mitigate the effect of herd immunity. Results There was no significant break in trend after rotavirus vaccine introduction (P = .46). Hazard ratio (HR) of celiac disease was 0.96 (95% CI 0.89-1.04) if born after compared with before vaccination started, and 1.00 (95% CI 0.92-1.09) when excluding children born in 2013-2015. In fully vaccinated compared with nonvaccinated the HR was 0.99 (95% CI 0.92-1.07), consistent in robustness analyses. Including a requirement for gluten-free diet support in the celiac disease case definition gave similar results (HR 1.06, 95% CI 0.98-1.15). Conclusions This study did not find an association between rotavirus vaccine and the risk of early-onset celiac disease.

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