Safety and effectiveness of the BNT162B2 mRNA COVID-19 vaccine in a nationwide cohort of patients with inflammatory bowel disease

ABSTRACT

BACKGROUND & AIMS: The effectiveness of currently available SARS-CoV-2 vaccines in patients with inflammatory bowel disease (IBD) remains unknown. We aimed to determine the effectiveness of the Pfizer-BNT162b2 mRNA vaccine in a nationwide cohort of patients with IBD in Qatar. METHODS: Using a cohort design, we compared 476 IBD patients vaccinated identified between January 1, 2021, and March 31, 2021, with 476 matched unvaccinated controls (matched on age and date of SARS-CoV-2 testing). Study outcomes included documented SARS-CoV-2 infection, symptomatic COVID-19, and COVID-19 related hospitalization. We also studied the side effects of the vaccination, including the effect on IBD exacerbation and hospitalizations related to adverse events. RESULTS: Total follow-up was 23,289 person-days for the vaccinated and 23,653 person-days for the unvaccinated group. Vaccine effectiveness >14 days [AAB1] after the second dose was 85.1% (95% CI 65.2, 93.6) for confirmed infection, and 87.1% (95% CI 63.6, 95.4)[AAB2] for symptomatic infection. No patient required hospitalization >14 days after the second vaccine dose. Estimated vaccine effectiveness between 22 to 35 days after the first dose was 14.8% (95% CI -151.5, 71.2) [AAB3] for any documented infection, and 59.8% (95% CI -106.1, 92.2) for symptomatic COVID-19 disease. For patients taking biologics with or without immunomodulators, vaccine effectiveness >14 days after the second dose was 94% (95% CI 53.1, 99.2), and 92.7% (95% CI 45.1, 99.0) for any documented infection and symptomatic COVID-19 respectively. Vaccine effectiveness was 87.4% (95% CI 46.0, 97.1) for any documented infection and 91.7% (95% CI 37.2, 98.9) for symptomatic COVID-19 during the same period for patients taking immunomodulators alone. None of the vaccinated patients required intensive care unit admission or died. No patient had IBD exacerbation or required hospitalization for vaccinationrelated adverse events. CONCLUSION: In a nationwide cohort of IBD patients, the BNT162b2 mRNA vaccine was safe and highly effective.