In this picture taken on April 29, 2020, an engineer (R) takes samples of monkey kidney cells as he makes a test on an experimental vaccine for the COVID-19 coronavirus inside the Cells Culture Room laboratory at the Sinovac Biotech facilities in Beijing. – Sinovac Biotech, which is conducting one of the four clinical trials that have been authorised in China, has claimed great progress in its research and promising results among monkeys. (Photo by NICOLAS ASFOURI / AFP) / TO GO WITH Health-virus-China-vaccine,FOCUS by Patrick Baert (Photo by NICOLAS ASFOURI/AFP via Getty Images)