Coronavirus: UK’s SAGE virologist says she ‘cannot exclude possibility’ of Wuhan lab leak theory

One of the UK’s top virologists today said she couldn’t rule out the possibility that the coronavirus had leaked out of a science lab in Wuhan.

But Professor Wendy Barclay, a member of the SAGE advisory group and infectious disease expert at Imperial College London, said she thought the accepted idea that the bug spread to humans in an animal market was ‘much more likely’.

Quizzed by MPs on the science committee this morning, Professor Barclay claimed viruses transmit from creatures to people in live markets ‘very, very frequently’. 

Her comments came amid growing doubts about the original theory that the virus emerged naturally, with critics lashing back against scientists who refused to entertain the idea it was being studied in a Chinese lab and escaped by accident.

US infectious diseases boss Dr Anthony Fauci has faced calls to resign over the scandal after he last year dismissed the theory as nonsense but appeared to be considering it behind closed doors.

And scientists who put their names to a letter denouncing the ‘lab leak’ theory last year have since changed their minds and said a full inquiry is required.

President Joe Biden has ordered a full investigation into the origin of the pandemic virus and demanded scientists work out whether there is truth to the theory.

Professor Wendy Barclay, a member of SAGE and infectious disease expert at Imperial College London, told MPs today that she ‘could not exclude the possibility’ of a lab leak but that a natural jump was more likely

The accepted wisdom has been that the virus emerged in a bat and then spread to people in the Huanan Seafood Market in Wuhan (pictured) in late 2019, but there is a growing counter-argument that the virus existed before this and could have been leaked from the Wuhan Institute of Virology nearby

The accepted wisdom has been that the virus emerged in a bat and then spread to people in the Huanan Seafood Market in Wuhan (pictured) in late 2019, but there is a growing counter-argument that the virus existed before this and could have been leaked from the Wuhan Institute of Virology nearby

Professor Barclay said today: ‘I’ll say with high confidence it came from an animal source. That’s my answer – high confidence it came from an animal.’

But the MP questioning her, Aaron Bell – a Conservative who represents Newcastle-under-Lyme in Staffordshire and sits on the science committee – probed further.

He asked: ‘Originally from an animal source, but is it possible that it was then being studied in a lab and it could have then leaked from the lab?’

Professor Barclay replied: ‘I cannot exclude that possibility.

‘But I would point out that we have instances of six other coronaviruses emerging into the human population where we don’t think that is the case. 

‘On the probability, I would say it’s much more likely, knowing where viruses are and live markets with animals mixed. For example, with the virus I’m more familiar with, influenza, that’s where you see zoonotic events happening very, very frequently.

‘I would suggest that the opportunity for the virus to jump from an animal source into humans in the part of the world where we first saw this virus emerge is very, very high.’

Professor Barclay’s comment comes after Boris Johnson on Sunday said ‘anybody sensible’ would ‘keep an open mind’ about the origin of the coronavirus outbreak but the UK does not currently believe the so-called ‘lab leak’ theory. 

Mr Johnson told a press conference at the end of the G7 summit in Cornwall: ‘At the moment, the advice that we have had is it doesn’t look as though this particular disease of zoonotic origin came from a lab.


No bats or pangolins were sold at Wuhan wet markets immediately before the coronavirus pandemic started, according to an Oxford-led study.

The research documents a menagerie of nearly 50,000 animals from 38 species, including badgers, boars, peacocks and pit vipers, traded at animal markets in the Chinese city from 2017 to November 2019.

But the team found ‘no evidence’ that a single bat or pangolin was kept at the market, leading them to conclude that these species – frequently blamed for Covid-19 – ‘were not the likely spillover host at the source of the coronavirus’.

Instead, they argued that the scores of wild animals kept in filthy cages and neglected by the merchants provided an abundance of routes for Covid-19 to pass on to humans.

Chris Newman, from the University of Oxford, told MailOnline: ‘Some of these species are known to host a variety of diseases.

‘A few have subsequently been identified as competent hosts of Covid-19, but the main suspected spill-over hosts, namely bats and pangolins, were not for sale in these markets.  

‘Our data cannot determine how humans became infected with Covid-19, only that direct contact with pangolins or bats in these markets seems highly implausible.’ 

‘Clearly anybody sensible would want to keep an open mind about that.’ 

The head of the World Health Organization insisted just a day earlier that the theory that Covid emerged from a Wuhan lab has not been ruled out – as he said China should help solve the mystery out of ‘respect’ for the dead.  

The body’s director-general, Dr Tedros Adhanom Ghebreyesus, suggested that Beijing had not cooperated fully as he urged more ‘transparency’ in the continuing investigation. 

There has been mounting controversy over how the virus first emerged – whether through animal contact at a ‘wet’ market in Wuhan or leakage from a highly secure research laboratory in the same city as some have suggested. 

China says it is not responsible for the pandemic and has dismissed theories about the disease being manmade.

However, last month Joe Biden ordered US intelligence agencies to report in the next three months on whether the Covid-19 virus first emerged in China from an animal or from a laboratory accident. 

Earlier this month one of the original authors of a controversial letter in The Lancet medical journal at the start of the pandemic said he had changed his stance on whether the lab leak was possible.

Dr Peter Palese, a microbiologist at the Icahn School of Medicine at Mount Sinai in New York, signed the letter in the Lancet in February last year claiming the virus could only have been natural in origin and to suggest otherwise would create ‘fear, rumors, and prejudice’.

The ‘bullying’ letter, orchestrated by Dr Peter Daszak, the head of a non-profit that funnelled U.S. taxpayer dollars to the Wuhan Institute of Virology, was criticized by experts for ostracizing anyone offering different opinions on the virus’ origins, dismissing them as conspiracy theorists.

It is only now, nearly 16 months after that letter was published in the world-renowned medical journal, that the theory Covid was accidentally leaked from a lab in Wuhan is being looked at seriously.

US President Joe Biden last week ordered intelligence agencies to launch a probe into whether Covid was man-made after all. But China immediately hit back and called the suggestion a ‘conspiracy’.

And now Professor Palese, 77, made a significant U-turn, admitting all theories on how Covid came about now need proper investigating.

He told MailOnline: ‘I believe a thorough investigation about the origin of the Covid-19 virus is needed. 

‘A lot of disturbing information has surfaced since the Lancet letter I signed, so I want to see answers covering all questions.’

Asked how he was originally approached to sign the letter and what new information had come to light specifically, Professor Palese declined to comment.

Professor Palese spoke out as America’s leading pandemic expert Dr Fauci continued to face fevered calls to resign after emails revealed that leading virus experts warned Covid could be man-made even as he downplayed the possibility.

The emails also showed he communicated with Dr Daszak, the head of the non-profit that funnelled U.S. taxpayer dollars to the Wuhan lab.

Biden threw his support behind the embattled expert on Friday, saying: ‘Yes I’m very confident in Dr Fauci.’ 

Another scientist who signed the letter, Dr Jeremy Farrar – director of the Wellcome Trust in London – declined to comment on the Fauci allegations but said it remains ‘most likely’ the virus came from an animal but ‘there are other possibilities which cannot be completely ruled out and retaining an open mind is critical’.