Adverse events following trivalent inactivated influenza vaccination in children: Analysis of the vaccine adverse event reporting system

Background: The Advisory Committee on Immunization Practices recommendations for influenza vaccination of children have expanded from the long-standing recommendation to vaccinate high-risk children aged 6 months, to vaccinating all 6- to 23-month-olds (2004), 2- to 4-year-olds (2006), and 5- to 18-year-olds (2008). Objective: To identify new or unexpected adverse events (AEs) after trivalent inactivated vaccine (TIV) in children. Methods: We analyzed reports after TIV to the Vaccine Adverse Event Reporting System from 1990-2006 in children aged 2 to 17 years, and from the 2008-2009 influenza season in children aged 5 to 17 years. Empiric Bayesian data mining techniques were used to identify new or unexpected AEs during 1990-2006. Results: During 1990-2006, the Vaccine Adverse Event Reporting System received 2054 reports of children aged 2 to 17 years with a peak in the 2003-2004 influenza season. In 2008-2009, 506 reports describing 5 to 17 year olds were received. The serious reports of tests performed after TIV were approximately 10% of all reports from 2001-2006, and 6% of the reports in the 2008-2009 season. Data mining showed an increased proportion of medication errors and Guillain Barré Syndrome (GBS). The findings of GBS could not be interpreted as causally related to vaccination. Among 201 reports of medication error, 94% had no AE reported other than the medication error itself. Conclusion: In this analysis, we found no unexpected AEs. Our review of medication error and GBS reports suggests that ongoing monitoring in these areas is appropriate.