A staff member of Sinovac Biotech, a Chinese biopharmaceutical company, cultivates Vero cells for production of COVID-19 inactivated vaccines in Beijing, capital of China, March 23, 2020. China's National Medical Products Administration on Friday granted conditional market approval to CoronaVac, an inactivated COVID-19 vaccine developed by Sinovac Biotech, the company said on Saturday. (Xinhua/Zhang Yuwei)