There have been renewed calls for the World Health Organisation (WHO) to be allowed to fully investigate the origins of the outbreak following reports that British agents believe it is”feasible” the pandemic began with a leak from the Wuhan Institute of Virology.
The development, which Beijing has angrily denied, prompted US diplomatic sources to share their concerns that “we are one wet market or bio lab away from the spillover,” The Sunday Times reported.
While scientists have backed calls for a thorough investigation into the origins of the coronavirus outbreak, they differ on how likely it is the virus escaped from a lab, with one telling The Independent it was “entirely plausible” and another saying such theories “vary from not credible at all to barely credible”.
A team of experts from WHO and China said in February that the virus was "extremely unlikely" to have entered the human population as a result of a laboratory-related incident, and was instead probably transmitted from bats to humans through another animal.
But since then, Dr Tedros Adhanom Ghebreyesus, director general of the WHO, has said he did not believe the initial report was "extensive enough" and has called for more research, adding that all hypotheses into the origins of the virus that causes Covid-19 "remain on the table".
“The lab leak theory is entirely plausible,” Dr Filippa Lentzos, a biosecurity researcher at King’s College London, told The Independent. “Safety lapses in the course of scientific research is a regular occurrence in labs all over the world, and we know there were several research teams in Wuhan working with coronaviruses.”
She added: “There is, as of yet, no concrete evidence for either natural spillover or a lab leak, but there is mounting circumstantial evidence for a lab leak, and the theory needs to be thoroughly and credibly investigated.”
Similarly, Robert F Garry, a virologist at Tulane University who analysed the genome sequence of the novel coronavirus, said he welcomed the investigation into its origins and added: “I hope the intelligence agencies take some of the scientific information into consideration. The Biden administration and the British agents should declassify this information ASAP, because it is being used to create uncertainty about Covid-19’s origins.”
However, he said he doubts that the pandemic emerged from a leak.
“At the same time I do not believe that the answers to the origins of SARS-CoV-2 lie in any type of forensic or intelligence-gathering operation surrounding the lab – this is a distraction.
There are numerous hypotheses that fall under lab leak – they vary from not credible at all to barely credible
Robert F Garry, virologist at Tulane University
“Rather, it’s imperative that we investigate the wildlife chain and find the reservoir of SARS-CoV-2. We also need an international effort to identify other coronaviruses that may become the next pandemic virus.”
Dr Garry went on to say it was “extremely unlikely” the pandemic came from a lab leak, adding: “There are numerous hypotheses that fall under lab leak – they vary from not credible at all to barely credible.”
Speculation the virus was engineered or otherwise manipulated is “not credible,” he said, because “there is absolutely no evidence for this, and much evidence to the contrary”.
Newly sequenced coronaviruses from bats captured in Cambodia, Thailand and Japan have different combinations of specific “spike motifs” first described in SARS-CoV-2, observations he said were “consistent with the natural origin of SARS-CoV-2 and strongly inconsistent with any type of laboratory origin”.
Similarly, Dr Garry said there was no evidence for the “barely credible” hypothesis the virus was present at the Wuhan Institute of Virology before the start of the pandemic. He said: “Before the pandemic there would have been no incentive to hide its existence and a large incentive to publish a scientific paper on a novel virus related to the first SARS-CoV.”
He added: “Lab leak scenarios are obviously inconsistent with several established facts regarding the origin of SARS-CoV-2, including the fact that the majority of early cases were linked to different markets that sold wildlife or wildlife products in Wuhan.”
A hybrid theory suggesting the coronavirus infected a scientist who was doing field work and then spread asymptomatically, or was released unknowingly after being brought back to a laboratory, is also “barely credible,” Dr Garry said. “Compared to the millions of worldwide encounters of humans with wildlife, including the trapping of bats for food, the number of high-risk exposures of scientists doing field or laboratory work with samples from wildlife is miniscule.”
Outbreaks of SARS between 2002-2004 were linked to the wildlife trade and a similar explanation is likely to account for the outbreak of the novel coronavirus, Dr Garry said.
“Several independent sources indicate that wildlife species susceptible to SARS-CoV-2, including civets and raccoon dogs, were sold at the Huanan market. Linkage of the origin of SARS-CoV-2 to wildlife or the wildlife trade fully accounts for the fact that the majority of early Wuhan Covid-19 cases were linked to different wildlife markets in a straightforward manner.
“It provides simple explanations for the fact that two different genetics lineages of SARS-CoV-2 were linked to different markets.”
While the balance of scientific evidence remains in favour of animal spillover, the possibility of an unintentional release from a laboratory working on coronaviruses needs to be thoroughly investigated otherwise the current speculation will never be dispelled
Lawrence S Young, virologist and professor of molecular oncology at Warwick Medical School
The “bottom line,” he said, was that the WHO and others should “follow the animals”.
Lawrence S Young, virologist and professor of molecular oncology at Warwick Medical School, said: “It is important that WHO have unfettered access to laboratory records from the Wuhan Institute of Virology.
“While the balance of scientific evidence remains in favour of animal spillover, the possibility of an unintentional release from a laboratory working on coronaviruses needs to be thoroughly investigated otherwise the current speculation will never be dispelled.
“It is vital that we fully understand the origin of SAR-CoV-2 to ensure that we can do everything to prevent another pandemic in the future.”
Similarly, Professor Dale Fisher, part of the WHO team that visited China, said the lab leak theory had not been ruled out but there was little evidence for it.
"China has had many instances where there has been whistleblowers before and to me that's another striking point here, is that there is no whistleblower," he told BBC Radio 4's The World This Weekend on Saturday.
"So, in fact, the only evidence in my mind for there being a lab leak is that there was a lab."
He added: "The lab leak theory is not off the table, there's more research to be done."
Charles Parton, a former diplomat who worked in China and senior associate fellow at the Royal United Services Institute (Rusi), told Times Radio on Saturday that if the virus had escaped a lab it would have been an accident.
He suggested efforts should be made to "keep the temperature down whatever is discovered".
He added: "It may be that scientists are clever enough without access to Chinese laboratory records to work out fairly conclusively over time how it came to come out and maybe it was a leak.
"If that's the case, and it's a big if, we should nevertheless not be too blaming because we have got to look to the future and try to get Chinese cooperation."
He said measures such as "UN nuclear inspection mechanisms" should be in place to monitor laboratories.
"I think in the immediate aftermath of this pandemic it's going to be a very sensitive matter to set that up because the Chinese will see that as an accusation of fallibility," he said.
It comes as the former head of the Food and Drug Administration (FDA), Scott Gottlieb, said lab leaks “happen all the time.”
Mr Gottlieb, who was promoting his book Uncontrolled Spread: Why COVID-19 Defeated Us and How We Can Beat the Next on CBS’s Face the Nation, said: “It’s important to understand what the possibility is that this came out of a lab so we could focus more international attention on trying to get better inventories around these labs, what they're doing, better security, make sure they're properly built. We need to also look at public health through the lens of national security,” he added.
“This was asymmetric harm to the United States. Covid hurt the US a lot more than it hurt many other countries.”