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The U.S. currently has the safest, most effective vaccine supply in its history. Vaccines are heavily regulated by the US Food and Drug Administration (FDA) and undergo years of extensive testing before reaching the public. Several systems monitor the safety of vaccines once they have been licensed and are in use. These include but are not limited to:

Vaccine Adverse Event Reporting System (VAERS): a national vaccine safety surveillance program co-sponsored by the CDC and the FDA. Through VAERS, health care professionals, patients, and vaccine manufacturers can submit reports about adverse events experienced after vaccination.

Vaccine Safety Datalink (VSD): a collaboration between the CDC and nine major healthcare organizations that uses electronic health data from each organization to help determine if side effects reported on VAERS are directly related to vaccination.

The FDA continually inspects vaccine manufacturing facilities to ensure vaccines are produced according to strict safety standards.

Vaccine safety resources

General vaccine safety

Autism and vaccines

Ingredients in vaccines

Multiple vaccinations and immune system

Religious and ethical considerations