title: Immune response to influenza vaccine in children with inflammatory bowel disease.
abstract: OBJECTIVE
  Patients with inflammatory bowel disease (IBD) frequently receive immunosuppressive therapy. The immune response in these patients to vaccines has not been well studied. We conducted a prospective, open label study to evaluate the serologic response to influenza vaccine in children with IBD.
  
  
  METHODS
  Serum was obtained from 146 children and young adults with IBD (96 Crohn's disease, 47 ulcerative colitis, and 3 indeterminate colitis) for baseline influenza titer, immediately followed by immunization with trivalent (A/Solomon Islands/3/2006 (H1N1), A/Wisconsin/67/2005 (H3N2), and B/Malaysia/2506/2004 (B)) inactivated influenza vaccine. Patients returned for repeat titers 3-9 weeks later. Seroprotection against each influenza strain was defined as hemagglutination inhibition titer > or = 40. Patients were categorized as nonimmunosuppressed (NIS; aminosalicylates only, antibiotics only, or no therapy) or immunosuppressed (IS; any immunosuppressive agent). IS patients were further subcategorized as: (i) tacrolimus, (ii) tumor necrosis factor-alpha (TNF-alpha) inhibitor, (3) immunomodulator, and (4) corticosteroids only.
  
  
  RESULTS
  More patients were seroprotected against strains A/H1N1 and A/H3N2 than B strain (P<0.02), regardless of immunosuppression status. The proportion of seroprotected patients and geometric mean titers at post-vaccination were similar between NIS and IS groups for all three strains. Subanalysis of patients not seroprotected at baseline showed that those receiving anti-TNF therapy were less likely to be seroprotected against strain B (14%) compared to patients in the NIS group (39%, P=0.025). There were no serious vaccine-associated adverse events.
  
  
  CONCLUSIONS
  Influenza vaccination produces a high prevalence of seroprotection in IBD patients, particularly against A strains. The vaccine is well tolerated. Routine influenza vaccination in IBD patients is recommended, irrespective of whether patients receive immunosuppressive medications.
authors.affiliation: Division of Gastroenterology, Hepatology, and Nutrition, Inflammatory Bowel Disease Center, Children's Hospital Boston, Boston, Massachusetts 02115, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Lu
authors.forename: Denise L
authors.initials: DL
authors.lastname: Jacobson
authors.forename: Lori A
authors.initials: LA
authors.lastname: Ashworth
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Grand
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Meyer
authors.forename: Monica M
authors.initials: MM
authors.lastname: McNeal
authors.forename: Matt C
authors.initials: MC
authors.lastname: Gregas
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Burchett
authors.forename: Athos
authors.initials: A
authors.lastname: Bousvaros
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016867:Immunocompromised Host; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D015212:Inflammatory Bowel Diseases / Q000276:immunology* / Q000628:therapy / Q000821:virology; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology*; D009981:Influenza B virus / Q000276:immunology*; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D011446:Prospective Studies; D019562:Viral Load; D055815:Young Adult
chemical_list: D007166:Immunosuppressive Agents; D007252:Influenza Vaccines