The incidence of Kawasaki disease after vaccination within the UK pre-school National Immunisation Programme: an observational THIN database study

Purpose To provide expected incidence rates of Kawasaki disease after vaccination in routine clinical practice and as recommended within a pre‐school National Immunisation Programme (NIP). Methods A post‐immunisation risk period when Kawasaki disease onset might be associated with vaccination was defined as 28 days. Immunisation records for children under 6 years were identified from The Health Improvement Network (THIN) database of electronic UK primary health care records (2008–2012) and linked to previously validated cases of Kawasaki disease with an assigned date of onset. Kawasaki disease incidence in the risk period after a complete NIP recommended set of vaccinations was estimated for five vaccination stages individually and in total. Results A total of 642 170 complete pre‐school immunisation stages from 275 986 children were included. Six cases of Kawasaki disease had onset in the risk period after any NIP stage providing an incidence of 12.8 per 100 000 person years (95%CI 5.7, 28.4). The incidence after any single immunisation stage ranged from 0 to 27.4 (95%CI 8.8, 84.8) per 100 000 person years. Conclusion There were few cases of Kawasaki disease in the risk period after any NIP vaccination combination. The incidence rates will aid in the interpretation of clinical trials and post‐marketing surveillance of new vaccines. Copyright © 2016 John Wiley & Sons, Ltd.