Was It a Lab Leak? The Mysterious Origin of COVID-19

Where did the virus that changed the world come from?

The prevailing theory for a long time was that wild animals sold as food at a wet market in Wuhan, China, had started the outbreak.

One of the first scientists to seriously question the official narrative was Botao Xiao, who in February 2020 published a pre-print paper arguing that "the killer coronavirus probably originated from a laboratory in Wuhan."

The author pointed out that there was no evidence that the vendors at the wet market in Wuhan sold bat meat. On the other hand, there were two research labs studying bat-borne coronaviruses located in Wuhan, where a virus could have accidentally infected workers, causing them to spread the disease to the general public. Xiao withdrew the paper two weeks later, after Chinese authorities declared that the lab-leak theory had no merit.

The Chinese government proceeded to clamp down on research into the virus's origins and ordered the closure of a lab that had shared the virus's genetic sequence with other scientists in January 2020. The government also forced the lab to destroy its viral samples.

To this day, the Chinese government won't allow outside researchers to test blood drawn from employees of the Wuhan Institute of Virology who, according to a U.S. intelligence report, were hospitalized for a flu-like illness in November 2019—weeks before the first documented human-to-human transmission. Chinese authorities cited privacy concerns to the World Health Organization (WHO) team that requested the samples.

There's no direct proof that the virus originated from a lab. But there's also no such proof that humans first became infected by eating bats or through exposure to pangolins, theories that were treated as unimpeachable fact early in the pandemic.