Emergency Use Authorization (EUA) is a mechanism used to facilitate the advancement of life-saving measures like vaccines during public health emergencies when diseases are posing serious or life-threatening risks. Because of the alarming rate of hospitalizations and deaths caused by COVID-19, the FDA approved EUA for certain COVID-19 vaccines after they went through rigorous testing and it was determined that the vaccines were safe and effective for use to protect against hospitalization and death related to COVID-19, and that benefits of the vaccines outweighed the potential risks. After the EUA was approved, manufacturing companies and other entities are still continuing monitor safety and efficacy of the vaccine, which includes following up with the individuals that participated in the clinical trials.