A man walks past posters encouraging people to have faith during the coronavirus outbreak in London, Britain on April 30, 2020. (Xinhua/Han Yan)

A worker disinfects an area outside a building in Rome, Italy, April 30, 2020. (Photo by Alberto Lingria/Xinhua)

Staff members of a private cleaning and disinfection company disinfect metro trains in Vincennes near Paris, France, April 30, 2020. (Photo by Aurelien Morissard/Xinhua)

Portuguese soldiers wearing protective gear prepare to disinfect a high school in Lisbon, Portugal, on April 29, 2020. (Photo by Pedro Fiuza/Xinhua)

A citizen stops at the famous city sculpture "Three Smiths" which has been put on facial masks, in Helsinki, Finland, March 31, 2020. (Xinhua/Zhu Haochen)