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Disease Epidemiology / Clinical Course / Other

1B-01 - DARWIN EU® - Background incidence rates of selected vaccine adverse events of special interest (AESIs) in Europe

Sunday, August 24, 2025
10:30 AM - 10:45 AM ET
Location: 207AB

    Presenting Author(s)

  • Xintong Li

    Postdoctoral data scientist
    University of Oxford, United Kingdom

    • Co-Author(s)

  • EB

    Edward Burn

    Health Data Sciences, Centre for Statistics in Medicine, University of Oxford, United Kingdom

  • DP

    Daniel Prieto-Alhambra

    Health Data Sciences, Centre for Statistics in Medicine, University of Oxford, United Kingdom

  • Albert Prats-Uribe

    Senior Clinical Research Fellow in Public Health
    NDORMS, Oxford University (UK), United Kingdom

  • Antonella Delmestri, PhD

    Lead Health Data Scientist
    University of Oxford, England, United Kingdom

  • MM

    Mees Mosseveld, MSc.

    Software Engineer
    Medical Informatics, Erasmus Medical Center, Netherlands

  • TD

    Talita Duarte Salles

    Fundació Institut Universitari per a la recerca a l’Atenció Primària de Salut Jordi Gol i Gurina (IDIAPJGol), Barcelona, Spain, Spain

  • HN

    Hedvig M.E Nordeng

    PharmacoEpidemiology and Drug Safety Research Group, Department of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway, Norway

  • AM

    Akram Mendez

    IQVIA Real World Solutions, United Kingdom

  • SH

    Saeed Hayati

    University of Oslo, Norway

  • NT

    Nhung TH Trinh, PharmD, PhD

    University of Oslo, Norway

  • AP

    Anna Palomar-Cros, PhD

    Epidemiologist
    Fundació Institut Universitari per a la recerca a l’Atenció Primària de Salut Jordi Gol i Gurina (IDIAPJGol), Barcelona, Spain, Spain

  • Agustina Giuliodori, PhD

    Data Scientist
    Fundació Institut Universitari per a la recerca a l’Atenció Primària de Salut Jordi Gol i Gurina (IDIAPJGol), Barcelona, Spain
    Barcelona, Catalonia, Spain

  • Katia Verhamme, MD, PhD

    Associate Professor of Use and Analysis of Observational Data
    Erasmus University Rotterdam (EUR) - Erasmus Medical Center (MC)
    Rotterdam, Zuid-Holland, Netherlands

  • GJ

    Gargi Jadhav

    IQVIA, Real World Solutions, London, United Kingdom, United Kingdom

  • JB

    James Brash, PhD

    Senior Data Scientist
    IQVIA, Real World Solutions, Brighton, United Kingdom, United Kingdom

  • AS

    Anna Saura Lazaro, MD, MPH, PhD

    Senior Epidemiologist
    University of Oxford
    Oxford, United Kingdom

Background: Since the pandemic, several publications have contributed to the global knowledge on background incidence rates of adverse events of special interest (AESIs), but regular updates are needed to remain prepared for new safety concerns.

Objectives: This study aimed to estimate the background incidence rates of 47 selected AESIs and understand the demographic and clinical characteristics of these patients in Europe during 2010-2024.

Methods: We conducted a population-level cohort study using primary care electronic health records and registries from five European countries (CPRD GOLD [UK], IPCI [The Netherlands], SIDIAP [Spain], NLHR [Norway], and IQVIA Germany).
We firstly developed the phenotypes for the 47 outcomes following the Standard Operating Procedure of DARWIN EU®. Some outcomes included multiple versions in favour of sensitivity or specificity.
We estimated incidence rates(IRs) of selected AESIs, stratified by time, sex, and age groups and we also reported the standardised incidence rates to the European population. For each incident AESI cohort, we constructed age-sex matched cohorts from the general population to compare the characteristics with the AESIs cohorts.

Results: Among immune-mediated diseases, Bell’s palsy was the most common outcome (overall IRs ranged from 25 (95%CI 25 - 26) per 100,000 person-years [Germany] to 66 (65 - 66) [SIDIAP]), while Kawasaki disease and Guillain-Barré syndrome were the rarest outcomes (ranged from 1.8(1.7 - 1.9)[CPRD] to 4.7 (4.4 - 5.1)[IPCI]). Among disorders of the nervous system, aseptic meningitis, encephalitis, myelitis, and optic neuritis had the lowest incidence rates of less than 10 per 100,000 person-years, while neuritis, non-epileptic seizure, and seizure were relatively more common.
Most outcomes had higher incidence for older age groups, although Kawasaki, type 1 diabetes, and seizures were more common in the youngest age groups. Detailed characteristics and IRs are presented at the online interactive app: data-dev.darwin-eu.org/aesi/
Where different definitions for an outcome were considered, the most pronounced difference in estimates was seen for neuritis, cardiomyopathy, and encephalitis.
For some outcomes, especially chronic conditions or those with extended progression, there was evidence of index date misclassification. Future studies, particularly those using self-controlled methods, should take this into consideration.

Conclusions: Backgrounds rates estimated from the current study were aligned with previous reports. We also detailed and contextualised cohort characteristics by comparing to the matched general population cohort. However, interpret these rates cautiously due to database heterogeneity and underlying time trends.