Kawasaki disease and 13-valent pneumococcal conjugate vaccination among young children: A self-controlled risk interval and cohort study with null results

BackgroundKawasaki disease is an acute vasculitis that primarily affects children younger than 5 years of age. Its etiology is unknown. The United States Vaccine Safety Datalink conducted postlicensure safety surveillance for 13-valent pneumococcal conjugate vaccine (PCV13), comparing the risk of Kawasaki disease within 28 days of PCV13 vaccination with the historical risk after 7-valent PCV (PCV7) vaccination and using chart-validation. A relative risk (RR) of 2.38 (95% CI 0.92–6.38) was found. Concurrently, the Food and Drug Administration (FDA) conducted a postlicensure safety review that identified cases of Kawasaki disease through adverse event reporting. The FDA decided to initiate a larger study of Kawasaki disease risk following PCV13 vaccination in the claims-based Sentinel/Postlicensure Rapid Immunization Safety Monitoring (PRISM) surveillance system. The objective of this study was to determine the existence and magnitude of any increased risk of Kawasaki disease in the 28 days following PCV13 vaccination.Methods and findingsThe study population included mostly commercially insured children from birth to p = 0.76). In the secondary, cohort analyses, which included roughly 700 potential cases and more than 3 million person-years, the risk estimates of potential Kawasaki disease in the risk interval versus in unexposed person-time were 0.84 (95% CI 0.65–1.08; p = 0.18) for the Days 1–28 risk interval and 0.97 (95% CI 0.79–1.19; p = 0.80) for the Days 1–42 risk interval. The main limitation of the study was that we lacked the resources to conduct medical record review for all the potential cases of Kawasaki disease. As a result, potential cases rather than chart-confirmed cases were used in the cohort analyses.ConclusionsWith more than 6 million doses of PCV13 administered, no evidence was found of an association between PCV13 vaccination and Kawasaki disease onset in the 4 weeks after vaccination nor of an elevated risk extending or concentrated somewhat beyond 4 weeks. These null results were consistent across alternative designs, age-adjustment methods, control intervals, and categories of Kawasaki disease case included.