Identification of the severe acute respiratory syndrome coronavirus 2 in humans toward the end of 2019 triggered a rapid, intensive effort to develop a vaccine. Among the first three COVID-19 vaccines granted emergency use authorization by the U. S. Food and Drug Administration (FDA) were two mRNA vaccines, never used on a large scale in humans, and one replication-incompetent human adenovirus vector vaccine. Since the beginning of the vaccination efforts in December 2020, almost 220,000 adverse events (AEs) have been reported through the Vaccine Adverse Event Reporting System, a reporting platform administered jointly by the FDA and the Centers for Disease Control to monitor vaccine-related AEs. We queried this database twice (04/23/21 and 05/14/21) and identified the AE reports with valid manufacturer-specific lot numbers (n = 76,336), a subset representing 33.54% of the total reported AEs. Using vaccine and demographic characteristics at the time of each query date, a model was generated to predict significant AEs, such as death. Our regression analysis revealed that the average age (IRR 1.08) and the number of doses administered in an assisted living facility (IRR 1.01) were significantly associated with the number of deaths observed in each lot, whereas the proportion of remaining vaccine shelf-life (IRR 1.30) and the vaccine manufacturer (IRR 1.09) were not. Studies such as this one are vital, as one of the best answers to vaccine hesitancy is reliable data confirming that the available COVID-19 vaccines are safe and not associated with a significantly higher risk of AEs than vaccines for other conditions.