Covid-19: FBI says pandemic ‘most likely’ caused by China lab leak - pandemic origin theories explained

The director of the FBI has said the bureau believes that Covid-19 “most likely” came from a lab leak in China.

Christopher Wray told Fox News: “The FBI has for quite some time now assessed that the origins of the pandemic are most likely a potential lab incident in Wuhan.” He also alleged that the Chinese Government has been “doing its best to try to thwart and obfuscate” efforts by the US and other countries to learn more about the origins of the coronavirus.

In response to the comments, which mark the first public confirmation of the FBI’s classified judgement on how the pandemic began, Beijing has accused Washington of “political manipulation”. Chinese foreign ministry spokeswoman Mao Ning added: “The conclusions they have reached have no credibility to speak of.”

Theories about the origins of Covid-19 have circulated since the pandemic first began in 2020, but none have enough evidence for definitive conclusions to been drawn. The FBI Director’s comments come just days after the Wall Street Journal reported that the United States’ Department of Energy had arrived at the same conclusion - supporting the ‘lab leak theory’ with “low confidence”.

However, the majority of other government agencies in the US, such as the National Intelligence Council, disagree - arguing instead that the virus originated in animals and was passed onto humans. But these beliefs also come with a “low level” of certainty, meaning other possibilities have not been able to be ruled out.

The ‘lab leak’ theory

One theory concerning how the Covid-19 pandemic began is that the virus was accidentally released by researchers at the Wuhan Institute of Virology. In this scenario, scientists who were studying coronaviruses are thought to have accidentally infected themselves - and passed the disease onto others.

Support for this comes from the fact that researchers at the laboratory in question were known to have been studying coronaviruses in the same family as SARS-CoV-2 - the strand which caused Covid-19 - around the time that the pandemic began.

But aspects of this theory soon spiralled out of control, with some alleging that the leak had been purposeful rather than accidental. However, this is refuted by the intelligence community, who, despite remaining split on what led to the virus, were aligned on certain points when they first issued a two-page, unclassified report in 2021:

• The virus was not developed as a biological weapon.
• The virus was not genetically engineered (two agencies however did not think there was sufficient evidence to make an assessment either way).
• Chinese officials did not have “foreknowledge of the virus” before the initial outbreak of Covid-19.

The ‘natural origin’ theory

The more generally accepted theory of how the coronavirus pandemic began is that SARS-CoV-2 spread naturally from animals to humans, in what is known as a ‘zoonotic’ jump. It is believed that this happened in Wuhan, China, at the city’s ‘wet market’.

A ‘wet market’ is where live animals are slaughtered and sold for human consumption. This includes, in some cases, wildlife such as bats - which is where the ‘bat theory’ began.

After the outbreak of Covid-19, China temporarily closed down its wet markets. It also made it illegal to sell live ‘wild’ animals - but not ‘common’ animals such as chickens or fish.

This theory is supported by the fact that 66% of the 41 patients initially hospitalised in China with an unknown pneumonia in January 2020 (later confirmed to be infections of the novel coronavirus), had had direct contact with the market. The theory also reflects the natural history of viruses and virus transmission.

When will we know what caused Covid-19?

Scientists may never be able to reach a conclusion on what caused the coronavirus pandemic, primarily due to a lack of definitive evidence. As of 2021, the World Health Organisation’s (WHO) official position is that it is “extremely unlikely” the virus came from the lab in Wuhan - but it did not completely rule it out.

The WHO instead said that the most likely explanation was that the virus originated in a bat before crossing to an intermediary animal and then jumping to humans.

However, the investigation was deeply criticised, and its director-general has even since called for a new inquiry, saying: “All hypotheses remain open and require further study.” Other governments across the world have called for the same.

Meanwhile, the White House’s national security spokesperson John Kirby has said that no official conclusion has been reached in the US - and, addressing the comments made by the FBI and Department of Energy, that “there is just not an intelligence community consensus.” But he also added that US President Joe Biden supports “a whole-of-government effort” to discover how the pandemic began.

The US ambassador to China, Nicholas Burns, also recently called for China to be “more honest about what happened three years ago in Wuhan, with the origin of Covid-19”.

Since the start of the pandemic, China has been criticised for not being cooperative enough in figuring out how the virus evolved.