More than two years into the pandemic, China is still sticking to its "zero Covid" policy, where polymerase chain reaction (PCR) tests, quarantines and flash lockdowns have almost become a part of "normal" life in the country.

With most cities now requiring nucleic acid tests done within the past 48 hours just to enter public spaces, offices and even schools, it is estimated that the testing could cost some 1.7 trillion yuan (S$350 billion) a year in China's major cities alone, or about 1.5 per cent of the country's gross domestic product.