The risk of severe covid-19 is not uniform

NABBING A DISEASEThe Economist Today hotspot is to epidemic control what locking up a serial perpetrator is to crime investigation. Success hinges on similar skills, as John Snow, an Englishman who drew up the principles of modern epidemiology, demonstrated in 1854. That year a cholera outbreak in central London killed more than 500 people in just two weeks. Snow investigated around 60 of those deaths and found a common factor: a contaminated water pump. Removing its handle ended the outbreak.