WHO report on COVID-19's Wuhan origins 'raises more questions than answers'

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More than a year after the coronavirus pandemic began, the World Health Organisation has released its report laying out how the virus spread to humans. But, reports The New York Times, it is already raising more questions than answers, including from the health bodyʼs own leader.

The report, drafted by a 34-member team of Chinese scientists and international experts who led a mission to Wuhan, China, examines a series of politically contentious questions, including whether the virus might have accidentally emerged from a Chinese laboratory.

Some members of the expert team have raised concerns about Chinaʼs refusal to share raw data about early COVID-19 cases. The NYT reports that in an unusual move, Dr Tedros Adhanom Ghebreyesus, the WHOʼs director-general, acknowledged those concerns while speaking about the report on Tuesday. He said he hoped future studies would include “more timely and comprehensive data sharing.”

According to the NYT, some take-outs from the report include the experts dismissing a lab leak theory, calling it “extremely unlikely.” The experts largely base their conclusion on conversations with scientists in Wuhan. But, Dr Tedros took the unexpected step of publicly raising doubts, saying that the theory required further investigation and that he was ready to deploy more experts to do so. “I do not believe that this assessment was extensive enough,” the NYT quotes him as saying at a briefing for member states on the report. “Further data and studies will be needed to reach more robust conclusions.”

Some critics have suggested that the team seemed to take the Chinese official position at face value and did not adequately investigate lab officialsʼ assertions. Raina MacIntyre, who heads the biosecurity program at the Kirby Institute of the University of New South Wales in Sydney, Australia, said in the NYT the report seemed to dismiss the idea of a lab leak “without strong evidence.” “A lab accident is certainly a possibility,” she said.

The NYT says another take out is that the role of animal markets is still unclear. The expert team concluded that the coronavirus probably emerged in bats before spreading to humans through an intermediate animal. But the team said there was not enough evidence to identify the species or to pinpoint where the spill-over of the virus from animals first occurred.

“No firm conclusion therefore about the role of the Huanan market in the origin of the outbreak, or how the infection was introduced into the market, can currently be drawn,” the report says. It says that further studies of farms and wild animals in China are needed, and that more clues about the marketsʼ role may emerge.

The NYT also notes that the inquiryʼs success will depend on China. The expert team offers a long list of recommendations for additional research: more testing of wildlife and livestock in China and Southeast Asia, more studies on the earliest cases of COVID-19 and more tracing of pathways from farms to markets in Wuhan.

But, the NYT says, it is unclear whether China, which has repeatedly hindered the WHO inquiry, will cooperate. Chinese officials have sought to redirect attention elsewhere, suggesting that the virus could have emerged in the US or other countries.

Experts say the delays in the inquiry have hurt the ability to prevent other pandemics. “This delay has obviously compromised the ability of the investigation to reconstruct the origins of COVID-19 and identify ways of reducing the risk of such events happening again in the future,” said Michael Baker, a professor of public health at the University of Otago in New Zealand.

 

Markets that sold animals – some dead, some alive – in December 2019 have emerged as a probable source of the coronavirus pandemic. Nature reports that the investigation winnowed out alternative hypotheses on when and where the pandemic arose, concluding that the virus probably didn’t spread widely before December or escape from a laboratory.

The investigation report also takes a deep look at the likely role of markets – including the Huanan market in Wuhan, to which many of the first known COVID-19 infections are linked.

“We could show the virus was circulating in the market as early as December 2019,” says the WHO’s Peter Ben Embarek, who co-led the investigation. He adds that this investigation is far from the last. “A lot of good leads were suggested in this report, and we anticipate that many, if not all of them, will be followed through because we owe it to the world to understand what happened, why and how to prevent it from happening again”.

Eddie Holmes, a virologist at the University of Sydney in Australia, says that the report does a good job of laying out what’s known about the early days of the pandemic – and notes that it suggests next steps for study. “There was clearly a lot of transmission at the market,” he says. “To me, looking at live-animal markets and animal farming should be the focus going forward.”

Nevertheless, exactly what happened at the Huanan market remains unknown. Genomic analyses and inferences based on the origins of other diseases suggest that an intermediate animal – possibly one sold at markets – passed SARS-CoV-2 to humans after becoming infected with a predecessor coronavirus in bats.

In late January and early February, 34 scientists from nations including China, Japan, the US and the UK gathered in Wuhan and assessed data. And now the team has published its findings in a 300-page report.

Much of it is devoted to COVID-19 cases occurring in December 2019 and January 2020. Two-thirds of the 170-odd people who had symptoms in December reported having been exposed to live or dead animals shortly beforehand, and 10% had travelled outside Wuhan.

Chinese researchers sequenced the genomes of SARS-CoV-2 from some of the people in this group, finding that eight of the earliest sequences were identical, and that infected people were linked to the Huanan market. This suggests an outbreak there, according to the report.

However, researchers also found that these genomes varied slightly from those in a few other early cases. Some linked to the market; others did not. This means that the coronavirus might have been spreading under the radar in communities, evolving along the way, and coincidentally occurring in people linked to the market, says the report.

Another possibility is that an outbreak occurred at a farm that provided animals to the market, suggests Holmes. Several infected animals – with slightly different variations of SARS-CoV-2 – might have then been sold at markets in Wuhan, sparking multiple infections in humans.

Nature says the findings are likely to be contested by some. A small group of scientists have sent letters to the media saying that they wouldn’t trust the outcome of the investigation because it was closely overseen by China’s government.

But others say that the WHO team’s conclusions seem solid. “I’m sure people will say that the Chinese researchers are lying, but it strikes me as honest,” argues Holmes. Matthew Kavanagh, a global-health researcher at Georgetown University in Washington, DC, says that he’s heard no evidence pointing to a lab escape. “But the sceptics are going to want a deeper investigation than the Chinese government allowed,” he says.

He adds that it’s challenging for the WHO to carry out such studies.

“The WHO is in a completely impossible position because they are being criticised for not holding China accountable, but they are given almost no tools to compel any country to cooperate,” he says. China holds information closely, and “in that context, the WHO’s team has gotten a good look at a lot of data – but it can only get so far”.

 

Robert Redfield, former director of the US Centres for Disease Control and Prevention was earlier quoted as saying he believes the virus that causes COVID-19 was accidentally released from a lab in Wuhan. USA Today reports that he offered no explanation for this idea other than to say as a virologist, he does not believe the virus could have been so contagious when it jumped directly from an animal to a person. Instead, he contends it was manipulated in a Wuhan research laboratory to become more contagious and then accidently released by a worker in September or October 2019, a few months before coming to public attention.

According to the report, however, several scientists said Redfield's theory did not pass the scientific smell test. "There's a fundamental difference between having a theory and testing a theory and showing evidence that your theory is a fact," said Paul Duprex, a virologist and director of the centre for vaccine research at the University of Pittsburgh.

Duprex, who runs a biosafety level three lab, which handles dangerous pathogens, said he would never rule out the possibility of human error. "No open-minded scientist will ever say to you, or should say to you, 'this is impossible," he said. "What a good scientist will say is, 'Where is the evidence?'"

USA Today reports that the WHO, which has been investigating the origins of the COVID-19 pandemic, considers the lab-leak scenario so unlikely it discontinued research in that hypothesis.

And W Ian Lipkin, director of the centre for infection and immunity at the Columbia University Mailman School of Public Health, said he thinks the virus jumped directly from animals to people – probably from wild animal farms, which the WHO team found operating in Wuhan.

“That seems to be the most likely and plausible explanation, particularly since we’ve seen so many of these viruses emerge in just this way,” he said, citing Zika, West Nile and the first SARS virus.

The WHO team examined the laboratory work of a number of researchers in Wuhan and found "no evidence at all that any of the labs in China were working on this virus prior to the outbreak," according to Peter Daszak, a team member and expert on animal-to-human diseases, who has also worked closely with one of the researchers in Wuhan.

"You can't prove a negative. You can't definitively say that wasn't going on," he said. "All you can do is look at what they were doing in that lab. What have they published from that lab. Did they have viruses that were the potential ancestor of SARS-CoV-2? Again, no evidence of that."

USA Today reports that Redfield emphasised he was expressing his personal opinion, not as a public official. Redfield, who trained as a virologist, said he came to the belief because of the speed at which the virus spread. He gave no evidence to support his belief that the virus began circulating in September or October 2019.

But, the report says, a genetic study published earlier this month found the first person was likely infected between mid-October and mid-November.

"This is not the time to add wild speculation to a global crisis," said Stephen Morse, a professor epidemiology at Columbia University's Mailman School of Public Health. "Speculation isn’t constructive, it doesn’t help us control the pandemic, and only distracts from the urgent work and global cooperation we need."

It has long been known that respiratory coronaviruses can spread efficiently from person-to-person. Four types of the common cold are caused by coronaviruses. "We just never really took them very seriously," Morse said.

Governments across the world, including in the US, Italy, Mexico, Brazil, made the same mistake, downplaying the virus in the early days, Morse said. They "should have paid more attention to this emerging problem back in January 2020.

 

Dr Anthony Fauci addressed Redfield's comments at a COVID-19 response briefing and suggested that most public health officials disagree. According to a CBS News report, he noted that if the virus had escaped from a lab, that would mean that "it essentially entered the outside human population already well-adapted to humans."

"However, the alternative explanation which most public health individuals go by, is that this virus was actually circulating in China, likely in Wuhan, for a month or more before they were clinically recognised at the end of December of 2019," Fauci said.

"If that were the case, the virus clearly could have adapted itself to a greater efficiency of transmissibility over that period of time, up to and at the time it was recognised. So, Dr Redfield was mentioning that he was giving an opinion as to a possibility, but again there are other alternatives – others that most people hold by."

CBS News reports that the current CDC director, Dr Rochelle Walensky, said at the briefing that she didn't "have any indication for or against" the hypotheses and that the White House team is "looking forward" to a report from the WHO that "examines the origin of this pandemic and of SARS-CoV-2 in humans."

 

Full report in The New York Times (Restricted access)

WHO report

Full Nature report (Open access)

Full USA Today report (Open access)

Full CBS News report (Open access)


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