"Importance. The United States Food and Drug Administration noted a potential safety concern for seizure in children aged 2-5 years receiving the ancestral monovalent COVID-19 mRNA vaccines.
Objective. To evaluate febrile seizure risk following monovalent COVID-19 mRNA vaccination among children aged 2-5 years.
Design, Setting, and Participants. ... A self-controlled case series analysis was performed in three commercial insurance databases to compare the risk of seizure in the risk interval (0-1 days) to a control interval (8-63 days)...
Results. The primary meta-analysis found a statistically significant increased incidence of febrile seizure in the 0-1 days following mRNA-1273 vaccination compared to the control interval (IRR: 2.52, 95% CI: 1.35 to 4.69, risk difference (RD)/100,000 doses = 3.22 (95%CI −0.31 to 6.75))."