A leaked Five Eyes report, a missing graduate student and an alleged cover-up by Chinese authorities: theories and conspiracies on the origin and spread of COVID-19 are running rampant, amplified by US politicians and Australian journalists.

So how did these theories start, and which ones hold their weight?

The theories

There are two main theories on COVID-19’s origin: that it came from animals, or that it was developed in a lab. 

Previous coronavirus strains, including Severe Acute Respiratory Syndrome (SARS) and the Middle East Respiratory Syndrome (MERS) were found to originate in bats.

But for a virus to jump from a bat to a human, it needs an intermediate host. Back in January, it was thought this host was a snake: snakes eat bats and were sold at the Wuhan wet market where the virus originated.

In April, a new theory emerged: pangolins, scaly anteaters, were the culprit. Two weeks ago, Germany’s leading COVID-19 expert Christian Drosten has also flagged a new theory — that the virus passed through raccoon dogs, which are widely sold in China for their fur.

Zoonotic transmission isn’t the only theory out there: a popular claim is the virus originated from the Wuhan Institute of Virology, with patient zero infected in the lab before the virus made it into the public.

China has responded with its own theory: that the virus originated in the US and was brought to China by the US army

The claims and the counterclaims

The zoonotic transmission theory has the most amount of scientific evidence: coronaviruses have been around for a long time with multiple studies conducted. Evidence shows the coronavirus which caused the 2003 SARS pandemic passed from bat to civet, while the strain which caused MERS jumped from bats to camels. 

The scientific consensus is that the virus that causes COVID-19 originated in horseshoe bats.

How a virus could survive in both cold and warm-blooded animals was a mystery, and the World Health Organisation (WHO) cast doubt in February over whether snakes could have been the intermediate host

Lung samples of Malaysian pangolins have been found to share 91% of their genetic sequence with COVID-19. The jury is out on pangolins, raccoon dogs and other animals.

So how about the lab theories? This theory has been touted by Fox host Tucker Carlson, US Secretary of State Mike Pompeo, and President Donald Trump. The Washington Post revealed the US government had expressed concerns since 2015 about safety standards and experiments — including bat coronaviruses — escaping from the lab

Last week Daily Telegraph political editor Sharri Markson authored a story on a leaked report from the Five Eyes intelligence agencies of Australia, Canada, New Zealand, the UK and US, stating the agency was looking at the work of two senior scientists at the Wuhan Institute of Virology. Both scientists had studied in Australia. 

Adding fuel to the flame is the alleged disappearance of graduate student Huang Yanling. She was rumoured on social media to be patient zero at the lab and was accused of reselling lab animals to wet market vendors. References to Yanling were scrubbed from the Chinese social media site Weibo and the lab’s website.

But the leaked Five Eyes report was more than three months old. In a separate story, Markson wrote the Australian government believes the chance the virus came from a lab was 5%. The Five Eyes network has also contradicted the theory, though it has raised concerns about China’s lack of transparency. 

In March, Shi Zhengli, a virologist at the Wuhan lab, spoke to the media explaining her research and concern that COVID-19 did leak from her lab. But genetic sequence testing shows COVID-19 did not match any viruses her lab previously tested. 

The WHO has also stressed the virus is believed to be “natural in origin“.

As for the theory the US created the virus, there doesn’t seem to be a lot of support: it originated from Lijian Zhao, a spokesman for China’s ministry of foreign affairs with a large Twitter following. Chinese state-run newspaper the Global Times has also reported the source of the virus remains undetected

The facts

  • First symptoms of COVID-19 were recorded on December 1, with a patient seeking medical help for pneumonia-like symptoms on December 8 in Wuhan
  • Four cases of a “pneumonia of unknown etiology” were reported in hospitals in the Hubei province on December 29
  • Samples from infected individuals arrived at Wuhan Institute of Virology on December 30
  • The WHO was alerted by Chinese authorities on December 31. The next day, the Huanan Seafood Wholesale Market — identified as a suspected centre of the outbreak — was closed
  • The virus spread to Thailand on January 13. Three days later, Japan reported its first case
  • Chinese officials secretly determined they were likely facing a pandemic on January 14, but only warned the public six days later on January 20. During that time, millions of people started travelling for Lunar New Year celebrations, while the city of Wuhan hosted a banquet for tens of thousands of people
  • Two days later, the WHO met to discuss whether to declare the outbreak an international health emergency. The next day, the WHO decided not to declare the outbreak a Public Health Emergency of International Concern (PHEIC)
  • On January 24, China extended travel restrictions or quarantines to 12 cities. On January 25 a doctor treating COVID-19 patients died from the virus in Wuhan. That same day, Australia confirmed its first case
  • By March 11, the WHO declared the coronavirus outbreak a pandemic