The first COVID-19 vaccine is being administered under an Emergency Use Authorization, or EUA. An EUA is submitted to the FDA during a public health emergency and allows medical countermeasures, such as vaccines, to be used before completing Phase 3 of the FDA approval process. Post authorization, the FDA, the CDC, and other healthcare agencies closely monitor vaccine safety and effectiveness.
Safety is a top priority during any vaccine approval process. Clinical trials are continually monitored for possible side effects, unexpected health events, or potential safety concerns. Even after FDA approval, the FDA conducts ongoing surveillance on vaccines. It is important to remember that no vaccine is 100 percent effective in preventing disease or 100 percent safe in all individuals despite rigorous and comprehensive safety protocols.