Vaccinations and immunization status in Paediatric inflammatory bowel disease: data from the VIP IBD study

Background: The prevention of vaccine preventable diseases (VPD) in children with inflammatory bowel disease (IBD) is an increasingly recognised issue. An ESPGHAN commentary providing specific recommendations on VPD was published in June 2012 (1). The aims of this study were to describe the compliance with these recommendations and to evaluate differences among patients diagnosed before and after June 2012. Methods: This retrospective, multicentre study included 12 pediatric IBD referral centres. The following data were collected from children with a diagnosis of IBD before and after June 2012: demographic details, diagnosis characteristics, therapies, vaccinations and immunization status at diagnosis and at the start of immunosuppressants (IM) and biologics, reasons for incomplete immunization and decision making on IM and biologics. Results: Between May and November 2016, 394 IBD children [Crohn's Disease (CD): 55.4%; Ulcerative Colitis (UC): 41.6%; Inflammatory Bowel Disease Unclassified (IBD-U): 3%] were enrolled. Among these, 50.2% and 48.8% were respectively diagnosed before and after June 2012. At diagnosis, the percentages of completion for single vaccination were: Diphtheria (99%), Tetanus (99%), Poliomyelitis (99%), Hepatitis B (99%), Pertussis (89%), Haemophilus Influenzae (69.3%), Pneumococcus (17.3%) Meningococcus C (23.9%), Measles (86%), Mumps (79.4%), Rubella (79.4%), Chickenpox (18.4%), HPV (4.1%) and Rotavirus (2%). Complete immunisation, according to the ESPGHAN commentary, was reported in 36% of the children. Among children with incomplete immunisation, specific vaccinations, before starting IM therapy, were recommended in 54.7% patients. In the remaining children, the reasons for not vaccinating were: need for immediate IM therapies (31.3%), parental refuse (8.4%), vaccination costs (3.4%) and other (56.9%). Two-hundred-fifteen (54.4%) out of 394 children started IM [Azathioprine: 204 (94.8%), Methotrexate: 9 (4.1%), other: 0.9%]. Among the children who started AZA, EBV status was only checked in 70 patients (34.3%), with 29 (41.4%) resulting EBV immunised and 41 EBV naive (58.6%). Biologics was started in 154 (39%) children [Infliximab: 79.8%, Adalimumab: 20.1%]. Tubercolosis screening before starting biologics was practised in 94.1% of children with different methods: Tubercolin Skin Test (38.6%), Quantiferon TB Gold (65.5%), T-SPOT TB (0.6%) and chest radiography (71%). Only 29.6% of patients yearly received influenza vaccination. No significant differences were identified between patients diagnosed before and after 2012 in all the analysed variables. Conclusions: This study suggests a poor compliance with the ESPGHAN recommendations, highlighting the need of new strategies to deal with VPD in IBD children.