The U.K.’s Coronavirus ‘Herd Immunity’ Debacle

Updated at 1:13 p.m. ET on March 16, 2020.

There was a time when it seemed possible for the world to contain COVID-19—the disease caused by the new coronavirus. That time is over. What began as an outbreak in China has become a pandemic, and as a growing number of countries struggle to control the virus, talk of “flattening the curve” is increasing. That is, a lot of people are going to get sick, and delaying infections as much as possible is imperative, so that cases occur over a long period of time and health systems aren’t suddenly inundated. Almost every country is trying to achieve this goal through the standard arsenal of public health—testing people and tracing contacts—and through more restrictive measures that include instituting quarantines, closing public spaces, banning mass gatherings, and issuing strong advice about social distancing.

But on Thursday, , Boris Johnson seemingly revealed that the United Kingdom would adopt a different strategy. The government would no longer try to track and trace the contacts of every suspected case, and it would test only people who are admitted to hospitals. In lieu of any major social-distancing measures, Johnson instead