A World Health Organization-led team investigating the origins of the Covid-19 pandemic said in a report that data examined during a recent mission to China was insufficient to answer the critical questions of when, where and how the virus began spreading.
The long-awaited report, which has yet to be made public but was reviewed by The Wall Street Journal on Monday, calls for closer examination of Chinese hospital records and blood samples from before the first known cases in December 2019, as well as more extensive testing of farms that supplied wild animals to a market linked to many early cases.
But the 319-page document, shared with WHO member states ahead of its planned publication on Tuesday, also recommends further studies into evidence, often cited by Chinese authorities, that the virus may have circulated in other countries—including the U.S.—in late 2019, and that it has spread via frozen food.
The report presents the findings of the four-week mission completed earlier this year by a WHO-led team of international experts and their Chinese counterparts in Wuhan, the Chinese city that was the site of the first confirmed coronavirus cases.
The team had little power to conduct a thorough, independent investigation during their trip. China initially resisted international pressure for an inquiry, and later imposed strict limitations, secured China veto rights over participants and expanded its scope to encompass other countries.