A medical worker inoculates a recipient with a COVID-19 vaccine at Peking University Hospital in Beijing, capital of China, Jan. 10, 2021. Beijing is slated to complete the inoculation for key groups before the Spring Festival, which falls on Feb. 12 this year. (Photos: Xinhua)

A medical worker inoculates a recipient with a COVID-19 vaccine at Peking University Hospital in Beijing, capital of China, Jan. 10, 2021. Beijing is slated to complete the inoculation for key groups before the Spring Festival, which falls on Feb. 12 this year.

A medical worker inoculates a recipient with a COVID-19 vaccine at Peking University Hospital in Beijing, capital of China, Jan. 10, 2021. Beijing is slated to complete the inoculation for key groups before the Spring Festival, which falls on Feb. 12 this year.

Medical workers check on people who were inoculated with COVID-19 vaccines at Peking University Hospital in Beijing, capital of China, Jan. 10, 2021. Beijing is slated to complete the inoculation for key groups before the Spring Festival, which falls on Feb. 12 this year.

A medical worker inoculates a recipient with a COVID-19 vaccine at Peking University Hospital in Beijing, capital of China, Jan. 10, 2021. Beijing is slated to complete the inoculation for key groups before the Spring Festival, which falls on Feb. 12 this year.