The origins of COVID-19 can’t be conclusively tied to the market in Wuhan where some of the first known cases appeared, according to Chinese researchers, further extending controversy around data collected at the start of the pandemic that had long remained out of view.
Findings from the samples taken more than three years ago have generated debate that intensified last month after the Chinese researchers briefly posted the data in an open-access genomics database. An outside group of academics who ran their own analysis concluded it was the strongest data yet backing the theory that the virus spilled over from animals to humans at the market. In a report published in the journal Nature, the Chinese researchers disagreed.
"The evidence provided in this study is not sufficient to support such a hypothesis,” according to the authors led by George Gao of the National Institute for Viral Disease Control and Prevention at the Chinese Center for Disease Control and Prevention in Beijing. While the study confirmed the existence of raccoon dogs and other animals susceptible to the virus at the market, the samples "cannot prove that the animals were infected. Furthermore, even if the animals were infected, our study does not rule out that human-to-animal transmission occurred.”