Why should live vaccines be delayed in children with Kawasaki disease?

Live vaccines should be delayed in children with Kawasaki disease primarily because of the use of aspirin. Kawasaki disease is characterized by inflammation of the blood vessels and can lead to significant cardiovascular complications. During the acute phase of the illness, high doses of aspirin are administered to reduce inflammation and prevent coronary artery aneurysms.

Aspirin is an antiplatelet medication that has potential implications for the immune system. Live vaccines contain weakened forms of viruses or bacteria that are intended to elicit an immune response. In children receiving high-dose aspirin, there is a theoretical risk of an incomplete immune response to these live vaccines, which could lead to an increased risk of vaccine-associated diseases or ineffective immunization.

After recovering from Kawasaki disease and no longer being on high-dose aspirin, children can typically resume their normal vaccination schedule, including live vaccines, once they are stable. This practice ensures that the child receives the full benefit of vaccinations without compromising their health or immune system integrity during a vulnerable period.