A staff member takes a swab sample for nucleic acid test at a testing point in Siming District of Xiamen, southeast China's Fujian Province, Sept. 22, 2021. Xiamen started to roll out its fourth nucleic acid test citywide on Wednesday. As of Sept. 21, a total of 194 COVID-19 cases have been reported and hospitalized in Xiamen. (Xinhua/Jiang Kehong)
