Safety

Safety at Every Step

Safety is incorporated into every level of vaccine development. Clinical trials are an important part of determining vaccine safety and effectiveness, generating scientific data for the Food and Drug Administration (FDA) to review and base their recommendations on.

Thousands participated in the COVID-19 vaccine clinical trials. The data demonstrate that the known and potential benefits of this vaccine outweigh the known and potential harms of becoming infected with COVID-19. Learn more about the trials for each manufacturer:

After the clinical trials help determine that a COVID-19 vaccine candidate is safe and effective, the Advisory Committee on Immunization Practices (ACIP), a committee comprising medical and public health experts, reviews available data before making vaccine recommendations to the Centers for Disease Control and Prevention (CDC). Learn more about how the CDC makes vaccine recommendations.


Safety Monitoring is Continuous 

After a vaccine is authorized for use, many vaccine safety monitoring systems watch for possible side effects. This continued monitoring can pick up on adverse events that may not have been seen in clinical trials. If an unexpected adverse event is seen, experts quickly study it further to assess whether it is a true safety concern that requires a change in recommendations. This monitoring is critical to help ensure that the benefits continue to outweigh the risks for people who receive vaccines. Learn more about vaccine safety monitoring.