As Scientific American reported in November 2020, the drop-off in flu numbers following COVID’s arrival was swift and global. Since then, cases have stayed remarkably low. “There’s just no flu circulating,” says Greg Poland, who has studied the disease at the Mayo Clinic for decades. The U.S. saw about 700 deaths from influenza during the 2020–2021 season. In comparison, the Centers for Disease Control and Prevention estimates there were approximately 22,000 U.S. deaths in the prior season and 34,000 deaths two seasons ago.