The holiday of Purim is a festival of life, recalling how the Jewish people escaped the genocidal plot of an evil minister against an ancient Persian king. In 2021, Purim again marked the saving of Jewish lives, but this time from a different enemy: SARS-CoV-2, the virus that causes COVID-19. Leaders of the U.S. Orthodox Jewish community—a group devastated by COVID-19 infections and deaths following Purim social gatherings in March 2020 before preventive measures such as masking and physical distancing became commonplace—were able before this year’s holiday to promote scientifically based safety guidelines for COVID-19-free celebrations. This was possible partly because of findings from a Johns Hopkins Medicine-led study evaluating just over 9,500 Orthodox Jews in 12 states that helped define the epidemiology of the Purim 2020 COVID-19 outbreak.