Pandemic prevention workers receive fresh protection equipment before their shift to looking after buildings where residents do home quarantine in Beijing on Dec. 8.THOMAS PETER/Reuters As many Chinese embraced new freedoms on Thursday after the country dropped key parts of its tough zero-COVID regime, there was mounting concern that a virus that had largely been kept in check could soon run wild. Three years into the pandemic, many in China had been eager for Beijing to start to align its rigid virus prevention measures with the rest of the world, which has largely opened up in an effort to live...