Michael Mina has long pushed for widespread testing as a way to stop COVID-19 outbreaks in their tracks. But what China is doing, he says, is going too far.

Wedded to a pandemic strategy that still seeks to eliminate every coronavirus case, the world’s second-most populous country is rolling out a vast network of testing booths in urban areas so that millions of people are within a 15-minute walk of getting swabbed at all times. Cities like Beijing, Shanghai, Shenzhen and Hangzhou are requiring tests as often as every 48 hours to access public transit, entertainment venues — and even workplaces.

While Mina, a former Harvard epidemiologist, was an early proponent of using inexpensive at-home tests to screen populations for initial cases of COVID-19 before they spread, he says China is taking the concept to another level. Entire cities and towns are covered by mass-testing mandates that require laboratory analysis, with results sent to health tracking apps on a person’s smartphone.