Who monitors the safety of vaccines?
CDC and FDA work together to closely monitor the safety of all U.S. vaccines. One tool that is used to monitor vaccine safety is the Vaccine Adverse Event Reporting System (VAERS). VAERS is a national reporting system that accepts and monitors reports of potential side effects following vaccination. CDC and FDA physicians and scientists review all reports of serious side effects reported to VAERS to identify potential new vaccine safety concerns that may need further study. It is important to know that reports of side effects after immunization are not conclusive proof that the side effect was caused by a vaccine. Some of the side effects reported to VAERS may occur by chance following vaccination. Factors such as the vaccine recipient’s medical history and other medications taken near the time of the vaccination must be reviewed to determine if they could have caused the side effect.
