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Is vaccination against COVID-19 associated with inflammatory bowel disease flare? Self-controlled case series analysis using the UK CPRD

Card, Timothy R; Nakafero, Georgina; Grainge, Matthew J; Mallen, Christian D.; Van-Tam, Jonathan S Nguyen; Williams, Hywel C; Abhishek, Abhishek


Clinical Associate Professor

Christian D. Mallen

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Professor of Dermato-Epidemiology


To investigate the association between vaccination against COVID-19 and inflammatory bowel disease (IBD) flare.

Patients with IBD vaccinated against COVID-19 who consulted for disease flare between 01/12/2020 and 31/12/2021 were ascertained from the Clinical Practice Research Datalink (CPRD). IBD flares were identified using consultation and corticosteroid prescription records. Vaccinations were identified using product codes and vaccination dates. The study period was partitioned into vaccine-exposed (vaccination date and 21-days immediately after), pre-vaccination (7-days immediately before vaccination), and the remaining vaccine-unexposed periods. Participants contributed data with multiple vaccinations and IBD flares. Season adjusted incidence rate ratios (aIRR) and 95% confidence intervals (CI) were calculated using self-controlled case-series analysis.

Data for 1911 IBD cases, 52% female, mean age 49 years, and 63% with ulcerative colitis (UC) were included. COVID-19 vaccination was not associated with increased IBD flares in the vaccine-exposed period when all vaccinations were considered (aIRR (95%CI) 0.89 (0.77-1.02), 0.79 (0.66-0.95), and 1.00 (0.79–1.27) in IBD overall, UC, and Crohn’s disease respectively). Analyses stratified to include only first, second or third COVID-19 vaccinations found no significant association between vaccination and IBD flares in the vaccine exposed period (aIRR (95%CI) 0.87 (0.71-1.06), 0.93 (0.75-1.15) and 0.86 (0.63-1.17) respectively). Similarly, stratification by COVID-19 before vaccination, and by vaccination with vectored DNA or mRNA vaccine did not reveal an increased risk of flare in any of these subgroups.

Vaccination against COVID-19 was not associated with IBD flares regardless of prior COVID-19 infection and whether mRNA or DNA vaccines were used.


Card, T. R., Nakafero, G., Grainge, M. J., Mallen, C. D., Van-Tam, J. S. N., Williams, H. C., & Abhishek, A. (2023). Is vaccination against COVID-19 associated with inflammatory bowel disease flare? Self-controlled case series analysis using the UK CPRD. American Journal of Gastroenterology, Publish Ahead of Print,

Journal Article Type Article
Acceptance Date Jan 20, 2023
Online Publication Date Feb 22, 2023
Publication Date Jan 30, 2023
Deposit Date Feb 2, 2023
Publicly Available Date Feb 2, 2023
Journal American Journal of Gastroenterology
Print ISSN 0002-9270
Electronic ISSN 1572-0241
Publisher Lippincott, Williams & Wilkins
Peer Reviewed Peer Reviewed
Volume Publish Ahead of Print
Keywords Gastroenterology; Hepatology
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