THE possibility the Covid virus leaked from a laboratory should not be ruled out, a former top Chinese government scientist has said.

As head of China's Centre for Disease Control (CDC), Professor George Gao played a key role in the pandemic response and efforts to trace its origins.

China's government dismisses any suggestion the disease may have originated in a Wuhan laboratory.

However, in an interview for a BBC Radio 4 podcast, Prof Gao says the hypothesis cannot be ruled out. 

In 'Fever: The Hunt for Covid’s Origin', Prof Gao said: “You can always suspect anything. That's science. Don't rule out anything.”

READ MORE: Covid 'lab leak' no longer just a conspiracy theory

Prof Gao, a world-leading virologist and immunologist, is now vice president of the National Natural Science Foundation of China after retiring from the CDC last year.

The eight-part BBC Radio 4 podcast, which will be available online from 11am on May 30, is the result of a three-year investigation into the possible origins of Covid. 

It includes interviews with some of the leading scientists from all sides of the debate, as well as on-the-ground reporting from Wuhan and from inside a high-security US laboratory.

The Herald:

The theory that the virus accidentally leaked from a laboratory was once dismissed as a conspiracy theory, but resurfaced in February when the FBI’s director said this is where it “most likely” originated.

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However, there is no consensus among US intelligence agencies on the question.

Many scientists say the weight of evidence suggests that a natural origin – the virus spreading from animals to humans – is the most likely scenario.

Wuhan is home to the Wuhan Institute of Virology (WIV), one of China's top national laboratories known to have spent years studying coronaviruses.

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In a possible sign that Chinese authorities may have taken the lab leak theory more seriously than its official statements suggest, Professor Gao said that the lab had been "double-checked by the experts in the field" - adding that he was referring to a formal search by a branch of the Chinese government.

It’s the first such acknowledgement that some kind of official investigation took place.

Professor Gao added that while he has not seen the result, he has “heard” that the lab was given a clean bill of health.

He said: “I think their conclusion is that they are following all the protocols. They haven't found [any] wrongdoing.”

The Herald:

The Chinese Embassy in the UK told the BBC: “The so-called ‘lab leak’ is a lie created by anti-China forces. It is politically motivated and has no scientific basis.”

Professor Gao also reveals that because the search for early cases in January 2020 was focused on Wuhan’s Huanan Seafood Market and hospitals near it, they may have missed a possible source of the virus on the other side of the city.

In February 2021, an investigation into Covid’s origin by the World Health Organization (WHO) said it was “extremely unlikely” the virus leaked from a lab.

Plans for a second phase of the investigation, involving audits of laboratories in the Wuhan area, were rejected by the Chinese government.

Professor Gao says he supports the continuation of the WHO’s investigation. However, he added that the WHO would need to “negotiate with the government”.

READ MORE: Disease X, Covid surveillance, and stopping the next pandemic

The series also speaks to Ian Lipkin, who is a professor of epidemiology at Columbia University in New York.

He was one of five co-authors of a March 2020 paper called 'The Proximal Origin of Sars-Cov-2', which concluded that “we do not believe that any type of laboratory-based scenario is plausible.”

However, Prof Lipkin now says that ruling out any lab-based scenario in the paper was putting it too strongly.

In an interview for the podcast, he says that while he stands by the conclusion that the virus was not deliberately engineered and that the market remains the most plausible explanation for where Covid came from, he does not feel all laboratory or research scenarios can be excluded.

The Herald: Dr Tedros Adhanom Ghebreyesus, WHO director-general recently announced that Covid-19 is over as a global health emergencyDr Tedros Adhanom Ghebreyesus, WHO director-general recently announced that Covid-19 is over as a global health emergency (Image: WHO)

He suggests that another Wuhan laboratory – run by the Wuhan Centre for Disease Control and located just a few hundred metres away from the Huanan Seafood Market - could be a source.

It was known to be involved in the collection of thousands of blood and faecal samples from wild bats.

According to Chinese news reports, this research was sometimes done without wearing proper protective equipment - a clear infection risk.

Prof Lipkin says that further analysis pointing to the Huanan Seafood Market as the origin of the virus - including recent research focused on evidence of raccoon dogs at the market - does not resolve the origin question.

The virus, he says, could have “originated outside of the market and been amplified in the market”.