(FILES) This file photo taken on February 23, 2017 shows workers next to a cage with mice (R) inside the P4 laboratory in Wuhan, capital of China's Hubei province. - The P4 epidemiological laboratory was built in co-operation with French bio-industrial firm Institut Merieux and the Chinese Academy of Sciences. The facility is among a handful of labs around the world cleared to handle Class 4 pathogens (P4) - dangerous viruses that pose a high risk of person-to-person transmission. (Photo by JOHANNES EISELE / AFP)