The U.S. Food and Drug Administration (FDA) issued an emergency use authorization (EUA) for the Pfizer-BioNTech COVID-19 vaccine on Dec. 11, 2020. A week later, the FDA issued an EUA for Moderna's COVID-19 vaccine. Now, nearly two years later, Pfizer and Moderna will launch clinical trials to track adverse health issues stemming from the COVID-19 vaccines, such as myocarditis – inflammation of the heart muscle. Pfizer is in the infancy of beginning clinical trials to determine if there are any health risks associated with their own vaccine. In a partnership with the Pediatric Heart Network, the trial will focus on...