title: Safety monitoring in the Vaccine Adverse Event Reporting System (VAERS).
abstract: The Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA) conduct post-licensure vaccine safety monitoring using the Vaccine Adverse Event Reporting System (VAERS), a spontaneous (or passive) reporting system. This means that after a vaccine is approved, CDC and FDA continue to monitor safety while it is distributed in the marketplace for use by collecting and analyzing spontaneous reports of adverse events that occur in persons following vaccination. Various methods and statistical techniques are used to analyze VAERS data, which CDC and FDA use to guide further safety evaluations and inform decisions around vaccine recommendations and regulatory action. VAERS data must be interpreted with caution due to the inherent limitations of passive surveillance. VAERS is primarily a safety signal detection and hypothesis generating system. Generally, VAERS data cannot be used to determine if a vaccine caused an adverse event. VAERS data interpreted alone or out of context can lead to erroneous conclusions about cause and effect as well as the risk of adverse events occurring following vaccination. CDC makes VAERS data available to the public and readily accessible online. We describe fundamental vaccine safety concepts, provide an overview of VAERS for healthcare professionals who provide vaccinations and might want to report or better understand a vaccine adverse event, and explain how CDC and FDA analyze VAERS data. We also describe strengths and limitations, and address common misconceptions about VAERS. Information in this review will be helpful for healthcare professionals counseling patients, parents, and others on vaccine safety and benefit-risk balance of vaccination.
authors.affiliation: Immunization Safety Office, Division of Health care Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States. Electronic address: TShimabukuro@cdc.gov.
authors.forename: Tom T
authors.initials: TT
authors.lastname: Shimabukuro
authors.affiliation: Office of Biostatistics and Epidemiology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Nguyen
authors.affiliation: Office of Biostatistics and Epidemiology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States.
authors.forename: David
authors.initials: D
authors.lastname: Martin
authors.affiliation: Immunization Safety Office, Division of Health care Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States.
authors.forename: Frank
authors.initials: F
authors.lastname: DeStefano
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D002487:Centers for Disease Control and Prevention, U.S.; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology* / Q000473:pathology*; D006801:Humans; D011358:Product Surveillance, Postmarketing; D014481:United States / Q000453:epidemiology; D014486:United States Food and Drug Administration; D014612:Vaccines / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D014612:Vaccines
keywords: Adverse effect; Adverse event following immunization; Adverse reaction; Passive surveillance; Spontaneous reporting; Vaccination; Vaccine Adverse Event Reporting System (VAERS); Vaccine adverse event; Vaccine safety