['Current guidelines emphasize vaccination for influenza and pneumococcus for IBD patients and the avoidance of live virus vaccines for those who are on immunosuppressive (ISS) therapy. Given the recent resurgence of measles and pertussis infections, we assessed the immune status of our IBD population in order to advise about these risks.', 'We prospectively collected measles and pertussis titers in our IBD patients from February 1-May 1, 2015. Immune status based on standard threshold values was determined: measles antibodies ≤0.8 antibody index (AI)\xa0=\xa0negative immunity, 0.9-1.1 AI\xa0=\xa0equivocal immunity and titers ≥1.2 AI\xa0=\xa0positive immunity. For pertussis immunity, anti-pertussis antibodies ≤5\xa0IU/mL were considered negative immunity. Univariate analysis was performed to examine predictive factors including age, disease duration, and current medical therapies.', "A total of 122 patients' titers were assessed (77 Crohn's disease, 1 indeterminate colitis, and 45 ulcerative colitis). Sixteen (13.1\xa0%) patients lacked detectable immunity to measles, and four (3\xa0%) had equivocal immunity. Twelve (75\xa0%) of the measles non-immune patients were on ISS therapy versus 65 (64\xa0%) of 102 immune patients (OR 1.7, 95\xa0% CI 0.5-5.9, p\xa0=\xa00.34). Out of 96 patients, 58 (60\xa0%) were not immune to pertussis. Disease duration ≥10\xa0years and age ≥50 were associated with significant lower measles titers."] Are many Inflammatory Bowel Disease Patients Immune to Measles or Pertussis?