At the public hospital in Shanghai where Nora, a 30-year-old doctor, works, tension has spiraled since China relaxed its stringent "zero-COVID" policy on Dec. 7.

Patients quarrel with doctors to access drugs that are in short supply, like cough medicines and painkillers. Medics are overloaded, and infected staff continue to work because of a scarcity of personnel.

"The policy of controlling COVID was relaxed very suddenly," said Nora, who would not give her full name because of the issue's sensitivity. "The hospitals should've been notified in advance to make adequate preparations."