Across Europe, dozens of babies have died of whooping cough and measles has surged across the globe. Meanwhile a flesh-eating bacteria is spreading at record rates in Japan, cholera has staged a comeback, and tuberculosis is rising in southeast Asia. In Brazil and Argentina, overwhelmed hospitals are teeming with dengue patients.

SARS-CoV-2 might have subsided, but the pandemic has been followed by a seemingly never-ending stream of nasties. T…