Vaccine Adverse Event Reporting System 

Vaccine Adverse Event Reporting System (VAERS) is a national early warning system to detect possible safety problems.  

VAERS accepts and analyzes reports of adverse events (possible side effects) after a person has received a vaccination.

  • An adverse event following vaccination is any untoward medical occurrence that follows vaccination and that does not necessarily have a causal relationship with usage of the vaccine. The adverse event may be any unfavorable or unintended sign, abnormal laboratory finding, symptom, or disease.

Anyone can report an adverse event following vaccination to VAERS: healthcare professionals, patients, or parents.

Healthcare professionals are required to report certain adverse events.



Vaccine Adverse Event Reporting System



Page last reviewed: December 3, 2021