Compared with most countries in the world, China has had a very low death rate during the Covid-19 pandemic, a record authorities attribute to the nation’s  “zero-tolerance” approach to fighting the disease. It adopted strict quarantine policies for foreign travellers and sometimes locked down whole cities to stem the flow of infection. But with the rise of highly infectious variants like Delta and Omicron, China has regularlybeen recording more than a hundred Covid cases each day since late…