The report, set to be released Tuesday, offers the most detailed look yet at what happened in Wuhan, China, in late 2019 and early 2020. However, the findings are far from conclusive and will be overshadowed by questions about China’s lack of transparency — and the WHO’s apparent inability to press for more.
The team recommends further study of the possible path of transmission between animals and humans and on transmission through frozen food — a once-fringe theory favored by the Chinese government. It does not recommend additional research on the lab leak hypothesis.
But WHO Director-General Tedros Adhanom Ghebreyesus, who was not part of the Wuhan mission, offered somewhat contradictory messaging at a news conference on Monday, saying “all hypotheses are open” and warrant future study.
Given China’s coverup of the outbreak in Wuhan, the WHO’s early praise for the country’s response and the fact that it took a full year to get a joint Chinese-international team on the ground for a brief visit, the critical but challenging search for clues faced skepticism from the start.
Secretary of State Antony Blinken told CNN last week he had concerns about “the methodology and the process,” including “the fact that the government in Beijing apparently helped to write it.”
“I don’t think the global community can have confidence in this report, because of China’s lack of transparency on necessary data sources, as well as the close relationship the team had to have with China,” said Larry Gostin, a professor of global health law at Georgetown University.
“This was an expert panel who worked diligently but were blocked from finding all that it could,” he continued. “As a result, we may never know the origins of the pandemic.”
Questions about Chinese interference will be hard to shake. The terms of reference set out by WHO member states called for a collaboration between Chinese and foreign scientists, not an independent investigation or audit. Much of the data was collected by Chinese scientists ahead of the visit and then analyzed by the joint team.
Among the report’s findings is that the market linked to early cases was not necessarily the source of the virus, as some once believed, but may have been the site of an early outbreak or an accelerator, as a virus that was circulating in December 2019 spread between close-packed stalls.
It notes the earliest reported case, from Dec. 8, did not have any link to the market, but it suggests that mild and asymptomatic cases may have gone undetected. The report, therefore, does not draw a firm conclusion and calls for additional research on the role of that and other markets.
According to the report, 233 Chinese health institutions reviewed 76,253 records of cases of respiratory conditions from October and November 2019, found 92 cases compatible with SARS-Co-V2 but later ruled out each case, concluding significant transmission before December was unlikely.
But the report questions whether the clinical criteria used to select those cases was sufficiently broad and notes that the results were based on serological testing conducted about a year later. It says the possibility of transmission before December 2019 cannot be excluded and recommends a review of methods and additional studies on Chinese blood samples.
The report reiterates the team’s belief that the virus most probably jumped from an animal, potentially a bat or pangolin, to an unknown intermediate animal host, then to humans, but the path of transmission remains a mystery. It recommends additional studies on livestock and farmed wildlife that may be susceptible to SARS-CoV-2, such as cats and mink.
The mission concludes it is extremely unlikely the virus accidentally leaked from a lab in Wuhan — a theory many scientists downplay for lack of evidence but that others are not ready to dismiss after a single visit.
The visit to the Wuhan Institute of Virology lasted a few hours, according to scientists on the trip. They got a tour of the facility, heard about the lab’s rigorous safety protocols and were told the lab was not working with viruses close to SARS-CoV-2.
One member of the team said in a post-trip television interview that researchers at the lab were sick in the fall of 2019 — a potentially interesting finding that had been raised by the Trump administration — but then dismissed its relevance and offered little else.
The final report states there was no direct infection of workers but does not go into detail or recommend further research on the topic.
It also notes that three laboratories in Wuhan were working with either coronavirus diagnostics or on isolation and vaccine development. All were “high quality” and “well managed,” it said, but it did not specify if the joint mission saw additional evidence, such as audits, to substantiate the claims.
The report also notes that a Wuhan Center for Disease Control lab moved Dec. 2, 2019 — a new detail — but that it “reported no disruptions or incidents caused by the move.”
The search for the origin of any virus is challenging, but the circumstances surrounding the first known cases of this one made launching a credible investigation particularly tough.
When a novel coronavirus hit Wuhan in late 2019, Chinese officials downplayed the risk, undercounted cases and silenced would-be whistleblowers. Then through the early weeks of the crisis, the WHO amplified some of the official Chinese line, giving a false sense of reassurance and eroding public trust.
Foreign scientists on the trip generally agree the timing and level of access was suboptimal but stressed that they were able to obtain information the world did not have before.
Even though the Huanan market had been shut for a year and its contents removed, for instance, seeing the proximity of the stalls and the layout helped, said WHO team member Hung Nguyen-Viet, a Vietnamese expert on livestock and human health.
In interviews, Hung and another expert on the trip, Keith Hamilton of the World Organization for Animal Health, said research on the market pointed to the need for additional investigation in southern China. It is unclear if China will allow foreign scientists to return.
Further questions about Chinese government influence will be raised by the report’s willingness to engage with the theory that the virus spread via frozen food — an idea touted by Chinese officials eager to suggest the pandemic originated outside the country. The report calls for additional research on whether the cold chain may play a role in transmission but casts doubt on the idea that early cases were imported to Wuhan. “This would be extraordinary in 2019 where the virus was not circulating widely,” it reads.
Still, the report ranks introduction through the cold chain as a “possible pathway,” of greater probability than a lab incident, which it describes as “an extremely unlikely pathway.”
Dominic Dwyer, an Australian microbiologist and infectious-disease expert on the mission, stressed that the team did not have the mandate, personnel or time to conduct a formal audit on labs.
“You could do, if so desired, a more detailed forensic examination,” he said. “But that is another whole negotiation and discussion.”
“What stands out starkly is that this is the kind of situation where member states are expecting results from WHO that they have not empowered it to produce,” said Mara Pillinger, a senior associate in global health policy and governance at Georgetown’s O’Neill Institute for National and Global Health Law. “They needed permission to go in, to conduct research and on the report.”
In general, the foreign scientists on the trip took pains to praise their Chinese counterparts, noting their technical expertise and professionalism. They also acknowledged the limits of working with data collected before they arrived that may or may not be complete.
“At the end of the day,” Hung said, “they show us what they show.”
Adam Taylor contributed to this report.