There are two important issues regarding immunization of children with KD: first, IVIG blocks the replication of live viral vaccines and the establishment of acquired immunity, so immunization should be delayed until at least 3 months after application of IVIG; and second, there are safety issues regarding the safety of live or other vaccines in children recovering from KD. Some autoimmune diseases, including systemic vasculitis, may deteriorate suddenly after administration of live or dead vaccines, so all vaccinations should be delayed for at least 3 months after KD. The AHA recommends that vaccinations against live, nonintestinal viruses (measles, mumps, and rubella) be delayed for at least 5 months after IVIG because passive immune antibodies may interfere with the immunologic function of immune preparations. However, during measles outbreaks, measles vaccine should be used early and with caution in children who have not been previously immunized with passive immunization, and the vaccine should be repeated at a later date. Other vaccinations should not be interrupted during childhood, and influenza vaccination is recommended to minimize the incidence of Reye′s syndrome in children with prolonged ASA.