A health worker registers a resident for a nasal spray COVID-19 booster vaccine in Beijing on Dec. 17.REUTERS TV/Reuters Streets in major Chinese cities were eerily quiet on Sunday as people stayed home to protect themselves from a surge in COVID-19 cases that has hit urban centres from north to south. China is in the first of an expected three waves of COVID-19 cases this winter, according to the country’s chief epidemiologist, Wu Zunyou. Further waves will come as people follow the tradition of returning en masse to their home areas for the Lunar New Year holiday next month, he...