Beijing insisted on Tuesday that it had shared information on Covid-19 "without holding anything back", after the World Health Organization implored China to offer more data and access to understand the disease's origins. Covid-19, which first emerged in the central Chinese city of Wuhan in December 2020, went on to kill millions of people, shred economies and overwhelm health systems. The WHO published a statement on Monday saying it was a "moral and scientific imperative" for China to share more information. In response, China defended its transparency, saying it had made the "largest contribution to global origin tracing research".