The hunt for the origin of the coronavirus continues.
Peter Ben Embarek displays a pathways-of-emergence diagram during the WHO press conference in Wuhan, China, on Feb. 9, 2021.
An expert group of investigators convened by the World Health Organization and China to examine the murky, complex origins of the coronavirus pandemic have revealed initial conclusions from a fact-finding mission that began just under two weeks ago. Liang Wannian, one of the scientists with China's National Health Commission, told reporters in a press conference Tuesday that the team hasn't found clear evidence of an animal-to-human spillover.
"We came here with two goals," said Peter Ben Embarek, a WHO expert in food safety and zoonosis (disease that's transmitted from animals to humans), "One was to try and get a better understanding of what happened at the beginning of the event in December 2019. In parallel, we also embarked on trying to understand ... how did the virus emerge."
Two hypotheses have arisen since the beginning of the pandemic. A majority of scientists believe SARS-CoV-2, the virus that causes COVID-19, originated in bats and made a jump into humans, potentially through an intermediate species. Another theory, gaining momentum in recent months, is the notion that a bat coronavirus may have been brought back to a Wuhan lab and then accidentally escaped.
The WHO's team of 14 scientists and researchers exited hotel quarantine in Wuhan on Jan. 28 and spent 12 days visiting sites in Wuhan, including the Huanan Seafood Market, where many of the early cases were found, and the Wuhan Institute of Virology, which was known to be researching bat coronaviruses and has been hypothesized as a site of an accidental laboratory leak.
Liang, team leader Ben Embarek and Marion Koopmans, a virologist at the Erasmus University Medical Center in the Netherlands, presented findings and took questions from journalists. They evaluated four hypotheses: a direct jump from animal to human, an introduction to humans via an intermediate host, the virus arriving in Wuhan via frozen food products and a lab-related incident.
See also: How many COVID-19 vaccinations in your state? How to track it
The conference was light on data, but of the four hypotheses, the team concluded that a lab origin is "extremely unlikely." A jump from a bat via an intermediate species is said to be the most likely.
"To me, the most important conclusion is that the virus is of natural origin," said Roger Frutos, a molecular microbiologist at the French Agricultural Research Centre for International Development, or CIRAD, not affiliated with the investigation. "It closes the door to the accident or engineering theories."
Other findings, as revealed by the panel:
China only agreed to an investigation into the origins after international pressure during the World Health Assembly in May 2020. Australia led the call for an independent inquiry into the origins, straining relations between the nations. Some scientists have suggested that while the investigative team has the expertise to trace the natural origins, it may not have the expertise for an investigation into a possible laboratory origin.
The press conference, which lasted just under three hours, didn't provide a whole lot of news and no data, but a full report is being prepared. It's uncertain when this will be ready. Ben Embarek made it clear the team has "been able to develop a series of recommendations for future studies." He said there is material, such as blood from blood banks, that might enable the team to get a better picture on the early days of the pandemic.