The virus that caused the COVID-19 pandemic is "extremely unlikely" to have originated in a lab, but most likely jumped from an animal to humans, according to a World Health Organization report released on Tuesday by a joint1 international and Chinese team probing the virus' origins.
The 120-page report said the virus most probably jumped from an animal, potentially a bat or pangolin, to an unknown intermediate animal host and then to humans. However, the path of transmission is still not known.
"There is no record of viruses closely related to SARS-CoV-2 in any laboratory before December 2019, or genomes that in combination could provide a SARS-CoV-2 genome," the report said.
"In view of the above, a laboratory origin of the pandemic was considered to be extremely unlikely."
The report said that the two most likely scenarios2 to explain the emergence3 of COVID-19 both involve the transmission of the virus from animals to humans.
"So far, we have not been able to document any substantial transmission of SARS coronavirus in the months preceding the outbreak in December," Thea Fisher, a member of the international team, said at a news conference on the report on Tuesday.