Immunogenecity of hepatitis A vaccine in pediatric patients with inflammatory bowel disease

Background: There are only a few studies on immune response to routine vaccinations in children with inflammatory bowel disease (IBD), despite a strong need for this kind of study. The aim of the study was to evaluate the immunogenicity of an inactivated hepatitis A vaccine (HAV) in IBD pediatric patients compared with healthy controls. Methods: This was an open, prospective, and controlled study on anti‐HAV‐negative children and adolescents age 2‐18 years with IBD. HAV using 720 enzyme‐linked immunosorbent assay (ELISA) units were administered at 0 months and at 6‐12 months. Seroconversion and geometric mean titers were measured after each vaccine dose. The evidence of local and systemic adverse effects for 3 days after the first and second dose of vaccine was registered. Results: A total of 134 subjects (66 patients and 68 controls) completed the whole study course consisting of two doses of vaccine and six serum samples. There was no significant difference in the rate of seroconversion between IBD patients and controls when measured after the second dose of vaccine (97% versus 100%, P = 0.2407), but the rate was significantly lower in the IBD group when measured after the first dose (39% versus 64%, P = 0.00001). The mean geometric titers were statistically significantly lower in the IBD group than in the control group at all of the measured timepoints. There were no serious adverse events related to HAV during the study. Conclusions: HAV is both immunogenic and safe in pediatric patients with IBD. (Inflamm Bowel Dis 2010;)