A medical worker collects swab samples for COVID-19 screening at a residential area in Dongchang District of Tonghua, northeast China's Jilin Province, Jan. 25, 2021. Tonghua on Monday launched the third round of citywide nucleic acid testing. (Xinhua/Xu Chang)

China's daily nucleic acid testing capacity has surpassed 15 million now. The country's overall testing capacity could further improve if the batch testing method is adopted, Chinese health department official Zeng Yixin said Wednesday.