Adverse Events Following Immunization: Will It Happen Again?

Parents may come to well-child checkup appointments equipped with lists of questions about vaccine safety and effectiveness. In this context, pediatricians may struggle to explain the value of vaccines when confronted with a difficult situation: an actual untoward event after administration of childhood vaccines. Often referred to as an adverse event following immunization (AEFI), 6 these events range from mild and uncommon to rare but serious. There are few experiences more challenging for a pediatrician than trying to convince a parent to continue vaccinating their child after they have witnessed a febrile seizure or a hypotonichyporesponsive episode (HHE) not long after a vaccination. Although studies have shown that these AEFI do not lead to adverse long-term consequences, 7 and thus subsequent vaccination is not contraindicated, 8, 9 this information is often not enough to convince these parents that the benefits of future vaccination outweigh potential risks. In this issue of Pediatrics, Zafack et al10 have provided valuable information to both pediatricians and parents confronted with such a situation. In the article, “Risk of Recurrence of Adverse Events Following Immunization: A Systematic Review, ” the authors quantify recurrence risk for numerous adverse events, including rare lifethreatening events such as anaphylaxis, as well as to more common benign events such as injection pain and redness. The article offers accurate, immediately useful information for the practicing pediatrician regarding AEFI and revaccination.