VAERS

VAERS, or the Vaccine Adverse Event Reporting System, is a national passive surveillance system in the United States for monitoring adverse events that occur after vaccination. It is jointly managed by the Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA).

VAERS collects reports from healthcare providers, vaccine recipients, and caregivers. Reports include information about the patient, the vaccine administered, the adverse event, time to onset, and the outcome. Submissions can be made online, by mail, or by telephone. In the United States, healthcare providers are required to report certain adverse events to VAERS, and vaccine manufacturers are required to report adverse events they become aware of; the public may also submit reports.

As a passive system, VAERS is used primarily as an early warning tool to detect potential vaccine safety signals that may require further study. It is not designed to determine causality or measure incidence on its own. Reports submitted to VAERS are not independently verified, can be incomplete or biased, and may describe events never caused by vaccines.

Data from VAERS are used by the CDC and FDA, in combination with other surveillance systems, to screen for unusual patterns and to guide further research. Publicly accessible VAERS data and summaries are published regularly to support transparency and independent analysis.

VAERS was established in 1990 under the National Childhood Vaccine Injury Act of 1986 as part of post-licensure vaccine safety monitoring. It remains a component of a broader vaccine safety infrastructure that includes additional systems and studies to evaluate potential safety concerns.