It is “extremely unlikely” that the coronavirus that causes COVID first emerged from a Chinese laboratory, a team of international experts said.
More than a dozen epidemiologists and disease experts, some working on behalf of the World Health Organization (WHO), traveled to the city of Wuhan last month with the aim of getting a better understanding of how the virus first transmitted to humans.
Dr. Peter Ben Embarek, a team leader of the mission, said in a press conference held in Wuhan on Tuesday, that experts were unable to get a conclusive answer of where the virus originated, but confirmed a laboratory leak hypothesis was rejected.
Since the outbreak first began in December 2019, conspiracy theories have suggested that COVID may have emerged from a laboratory, even as scientists continued to stress that existing evidence widely pointed to the source being of a natural origin.
Dr. Embarek said: “Our initial findings suggest that the introduction [of the SARS-CoV-2 coronavirus] through an intermediary host species is the most likely pathway and one that will require most studies and more specific targeted research.
“Similarly, connected to that hypothesis, is also the one including the possibility of transmission through the trade of frozen products.
“The hypothesis of a direct spillover from an original animal source into the population is also a possible pathway and is also generating recommendation for future studies.
“However, the findings suggest the laboratory incident hypothesis is extremely unlikely to explain the introduction of the virus into the human population.”
He said that the lab hypothesis would not be used as the basis for future research into virus origins.
Peter Daszak, another expert on the mission, said on Twitter that the decision among the team about the possibility of a laboratory leak was “a unanimous one.”
Dr. Embarek said during the press briefing on Tuesday that the lab incident hypothesis was discarded after analyzing and weighing up the available evidence.
He acknowledged that virus outbreak accidents had occurred globally in the past but noted this particular coronavirus strain was not previously identified or known.
He added: “We looked, for example, at the Wuhan Institute of Virology and the state of that laboratory. It was very unlikely that anything could escape from such a place.”