Mainland China has good reasons to stick with its current strategy, though, Sean Sylvia, an assistant health-economics professor at the University of North Carolina at Chapel Hill, told me in an email. The country’s health-care system is weak and poorly resourced. China’s population density is high and immunity is lower because of lack of exposure to the virus. The Omicron variant, he wrote, provides a new test, as it makes maintaining low case numbers more challenging while at the same time increasing the potential costs of relaxing controls.

Vaccination rates are high on mainland China, about 88 percent, but mRNA vaccines are not available. The German firm BioNTech has been waiting months for approval to enter the Chinese market. (The BioNTech shot is available in Hong Kong and Macau. Though BioNTech partners with Pfizer for its distribution in most countries, its vaccine is distributed in Hong Kong and Macau through a deal with China’s Fosun Pharma.) China has not developed its own mRNA jab. It is reliant on the Chinese-developed Sinopharm and Sinovac shots. These “inactivated virus” vaccines have proved to be less effective at stopping COVID deaths, according to data compiled in Singapore…

Yanzhong Huang, a senior fellow for global health at the Council on Foreign Relations, in Washington, D.C., told me that the Chinese authorities are asking vaccines to do the impossible. “Even the best vaccines in the world cannot prevent infection,” he said. Zoe Liu, a 22-year-old from Tianjin, in northern China, wonders if constant testing doesn’t undercut Beijing’s messaging about the positives of being vaccinated, and she is unhappy with the costs of canceled travel and medical services. “It is not just wasting the resources of our country,” she told me, “but wasting the money in my pocket.”