China

The first time the Omicron variant breached Hong Kong’s coronavirus defenses, in late 2021, the city stamped it out, cementing its status as one of the world’s most formidable redoubts of “zero Covid.”

But a few weeks later, Omicron came to the metropolis again, this time causing an outbreak among cleaners at a public-housing estate that spiraled out of control. The conflagration of resulting cases is now killing people at a rate exceeding that of almost any country since the coronavirus emerged.