Medical staff work at a COVID-19 testing lab in Shunyi district of Beijing, Jan 3, 2021.[Photo by Zou Hong/chinadaily.com.cn]

A staff member introduces a platform showcasing nucleic acid testing information of Beijing at a testing institution in Shunyi district of Beijing, Jan 3, 2021. [Photo by Zou Hong/chinadaily.com.cn]

A health worker (L) registers personal information at a COVID-19 testing site in Shunyi district of Beijing, Jan 3, 2021. A new round of nucleic acid testing was launched in the district after a new locally transmitted COVID-19 case was reported. [Photo by Zou Hong/chinadaily.com.cn]

Medical workers collect throat swabs from residents at a nucleic acid testing site in Shunyi district of Beijing, Jan 3, 2021. [Photo by Zou Hong/chinadaily.com.cn]