WUHAN, China (AP) – Coronavirus probably first appeared in humans after jumping from an animal, a team of international and Chinese scientists looking for the origins of COVID-19, said an alternative theory on Tuesday that the virus leaked from a Chinese laboratory was unlikely.
A closely monitored visit by World Health Organization experts to Wuhan (the Chinese city where the first cases of coronavirus were discovered) did not dramatically change the current understanding of the early days of the pandemic, said Peter Ben Embarek , the leader of the WHO mission.
But he “added details to this story,” he told a news conference as the group ended a four-week visit to the city.
And it allowed the Chinese-WHO joint team to further explore the theory of laboratory leaks – which former U.S. President Donald Trump and officials in his administration had presented without evidence – and decided it was unlikely. The Wuhan Institute of Virology is home to many different virus samples, which meant it could have been the source of the original outbreak, either on purpose or by accident.
Embarek, a WHO expert on food safety and animal diseases, said experts now consider the possibility of such a leak to be so unlikely that it will not be suggested as a future avenue of study. But another team member, Danish scientist Thea Koelsen Fischer, told reporters that team members could not rule out the possibility of further investigations and new contacts.
China had already strongly rejected the possibility of a leak and has promoted other theories. Chinese and foreign experts considered various ideas about how the disease first ended in humans, leading to a pandemic that has killed more than 2.3 million people worldwide.
Embarek said initial findings suggest the most likely route the virus followed was from one bat to another animal and then to humans, adding that more research would be needed.
“The findings suggest that the laboratory incident hypothesis is unlikely to explain the introduction of the virus into the human population,” he said.
When asked why, Embarek said accidental releases are extremely rare and that the review of the Wuhan Institute’s laboratory operations team indicated that it would be difficult for anything to escape.
He also noted that there were no reports of this virus in any laboratory anywhere before the pandemic. Liang Wannian, the head of the Chinese side, also emphasized this, saying there was no sample at the Wuhan institute.
The mission was intended to be an initial step in the process of understanding the origins of the virus, which scientists have claimed can pass to humans through a wild animal, such as a pangolin rat or bamboo. Direct transmission of bats to humans or through trade in frozen food products are also possibilities, Embarek said.
The visit of the WHO team is politically sensitive for Beijing, worried about being blamed for alleged mistakes in its first response to the outbreak. An AP investigation has been found that the Chinese government put limits on the investigation of the outbreak and ordered scientists not to talk to reporters.
However, a member of the WHO team, British-born zoologist Peter Daszak, told The Associated Press last week that they enjoyed a higher level of openness than they had anticipated and that they were granted full access to all the posts and staff they requested.
Koelsen Fischer said he failed to see the raw data and had to rely on an analysis of the data presented to him. But he said that would be true in most countries.
The team, which includes experts from 10 countries who arrived on January 14, visited the Huanan Seafood Market, the place where the first case groups occurred in late 2019.
Marion Koopmans, the team’s Dutch virologist, said some animals on the market were susceptible or suspected of being susceptible to the virus, including rabbits and bamboo rats. And some could be sought on farms or traders in regions where bats carrying the related virus closest to that caused by COVID-19 are found.
He said the next step would be to look more closely at the farms.
Liang, the head of the Chinese team, said the virus also appeared to have spread to different parts of the city from the market, so the virus may have originated elsewhere.
The team found no evidence that the disease spread long before the initial outbreak in the second half of December 2019.
“We have not been able to do the research completely, but there are no indications that there were clusters before what we saw happen in the final part of December in Wuhan,” Liang said.
The visit of the WHO team took months to negotiate. China only accepted it amid international pressure at the WHO World Health Assembly meeting last May, and Beijing has continued to resist requests for a strictly independent investigation.
Although China has withstood some localized resurgence of infection since the outbreak was controlled last year, life in Wuhan has largely returned to normal.
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Associated Press writers Ken Moritsugu in Beijing and Jan M. Olsen in Copenhagen, Denmark, contributed to this report.