Vaccines 2026, 14(6), 474; https://doi.org/10.3390/vaccines14060474 - 26 May 2026
Abstract
Introduction: Live attenuated vaccines (LAVs) are generally avoided in patients with inflammatory bowel disease (IBD) receiving immunomodulatory therapy due to concerns about infection risk. However, real-world data evaluating their safety in this population remain limited. We aimed to assess adverse outcomes following LAV
[...] Read more.
Introduction: Live attenuated vaccines (LAVs) are generally avoided in patients with inflammatory bowel disease (IBD) receiving immunomodulatory therapy due to concerns about infection risk. However, real-world data evaluating their safety in this population remain limited. We aimed to assess adverse outcomes following LAV administration in IBD patients treated with biologic agents. Methods: We conducted a retrospective cohort study using the TriNetX multi-institutional database. Adults with IBD receiving immunomodulatory therapy were categorized into two cohorts: those who received an LAV and those who did not. Biologic therapies included tumor necrosis factor inhibitors (infliximab, and adalimumab), integrin antagonists (vedolizumab), interleukin (IL)-12/23 inhibitors (ustekinumab), IL-23 inhibitors (risankizumab, and guselkumab), and Janus kinase inhibitors (tofacitinib, and upadacitinib). LAVs included measles–mumps–rubella (MMR), varicella (Varivax), and yellow fever vaccines. Propensity score matching was performed based on age, sex, IBD subtype (Crohn’s disease vs. ulcerative colitis), and biologic class. Patients with outcomes prior to the risk window were excluded. Adverse outcomes within six months included hospitalization, emergency department (ED) visits, fever, rash, and encephalitis. Results: A total of 672 patients were included in each propensity-score-matched cohort. Live attenuated vaccine (LAV) administration was not associated with significantly increased adverse outcomes compared with no LAV exposure during the six-month follow-up period. Hospitalization occurred in 14.9% versus 15.3% of patients, respectively (risk ratio [RR] 0.97; 95% confidence interval [CI] 0.75–1.25; p = 0.819), while emergency department visits occurred in 12.6% vs 11.3% (RR 1.12; 95% CI 0.84–1.50; p = 0.450). There were no significant differences in fever (3.6% vs. 3.3%; RR 1.09; 95% CI 0.62–1.93; p = 0.764) or rash (4.0% vs. 2.7%; RR 1.50; 95% CI 0.83–2.70; p = 0.172). No cases of measles, mumps, rubella, varicella, yellow fever, or encephalitis were identified in either cohort during follow-up. Conclusions: LAVs were not associated with an increased risk of adverse outcomes within one day to six months among IBD patients receiving immunomodulatory therapy. These real-world findings suggest comparable short-term outcomes between the cohorts of patients with IBD receiving biologic or targeted synthetic therapy who met the predefined eligibility criteria including age ≥ 18 years, and vaccination occurring between two weeks and six months after biologic initiation regarding LAV use in patients with IBD receiving biologic agents.
Full article
(This article belongs to the Section Vaccination Against Cancer and Chronic Diseases)
►
Show Figures
Figure 1
