The Pfizer-BioNTech and Moderna COVID-19 vaccines have all undergone Phase III clinical trials conducted worldwide with almost 75,000 volunteers. Vaccine makers are required to track any adverse reactions that vaccine trial participants have. To do this for the COVID-19 vaccines, they have collected data on thousands of participants for at least one month after both doses to ensure that they haven’t had any unexpected reactions to the vaccine.

The vaccines are then reviewed by the federal Advisory Committee on Immunization Practices and the FDA’s Vaccines and Related Biological Products Advisory Committee, a group of infectious disease, pediatric and vaccine medical experts, who will only grant an EUA to use a vaccine that has demonstrated quality and safety during clinical trials.

Before they can be used in Washington state, the vaccines must also be reviewed by the Western States Scientific Safety Review Workgroup, which reviews the vaccines to ensure their safety before they are used in Washington, Oregon, Nevada, Colorado and California.

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