July 19 was meant to mark the end of pandemic lockdown restrictions in England, as progress continued in vaccinating people against Covid-19. But just as the country relaxed most restrictions, it was still dealing with a third wave of coronavirus infections as the highly contagious delta variant spread across the UK. A record number of people who had come into contact with an infected person were being asked to self-isolate, most of them having been “pinged” by the National Health Service’s contact-tracing app. The “pingdemic,” as it’s been dubbed, has produced enormous disruptions for businesses and critical services that threaten to undermine efforts to revive an economy still recovering from its deepest recession in 300...