Vaccine-associated Kawasaki disease in children

Kawasaki disease (KD) is a leading cause of heart disease in children. The etiology of KD is currently unknown. The onset of KD occurs with delays following pathogen outbreaks and also post-immunization. A recent etiology model of KD proposed that KD is caused by activation of mast cells and likely platelets. Recently, it was discovered that epilepsy safety signals were associated with specific vaccines for infants aged 0 and 1. The problem statement of this paper is whether these safety signals also appear in children post-immunization. Herein, the Vaccine Adverse Event Reporting System was retrospectively examined for KD adverse events (AEs) for children. The same pattern of safety signals was observed with KD AEs as epilepsy AEs post-immunization. KD associated with vaccination (KD-V) is associated with either a pattern consistent with direct innate immune activation or immune complex activation of mast cells and likely platelets. Candidate causative factors identified include live virus vaccines and very high dosage levels for specific infant vaccines and specific concomitant combinations. Adjusting vaccine dosage based on infant body size for several vaccines is strongly recommended, including adjusting the infectious units in attenuated live viral vaccines. Concomitant administration of specific vaccines results in either additive or synergy risk levels for KD. Concomitant administration of specific vaccines, including attenuated live viruses with synergy KD risk levels, is strongly recommended against (counterindicated).