US intelligence agencies say it is unlikely they will ever be able to conclude whether Covid-19 spread by animal-to-human transmission or leaked from a lab.
The paper issued by the Director of National Intelligence elaborates on findings released in August of a 90-day review ordered by President Joe Biden.
That review said that US intelligence agencies were divided on the origins of the virus but that analysts do not believe the virus was developed as a bioweapon and that most agencies believe the virus was not genetically engineered.
China has resisted global pressure to cooperate fully with investigations into the pandemic or provide access to genetic sequences of coronaviruses kept at the Wuhan Institute of Virology (WIV), which remains a subject of speculation for its research and reported safety problems.
Mr Biden launched the review amid growing momentum for the theory — initially broadly dismissed by experts — that the virus leaked from the Wuhan lab.
Former President Donald Trump and his supporters long argued that a lab leak was possible as they sought to deflect criticism of his handling of the pandemic.
China remains an exceedingly difficult place for intelligence operations and has fought back against allegations that it mishandled the emergence of the pandemic, which has killed 5 million people worldwide.
Senior officials involved in the full report’s drafting said they hoped it would better inform the public about the challenges of determining the virus’s origins.
“We don’t think we’re one or two reports away from being able to understand it,” said one official, who spoke on condition of anonymity to discuss intelligence matters.
The full report notes that the Wuhan Institute of Virology “previously created chimeras, or combinations, of SARS-like coronaviruses, but this information does not provide insight into whether SARS Cov-2 was genetically engineered by the WIV.”
Information that lab researchers sought medical treatment for a respiratory illness in November 2019 “is not diagnostic of the pandemic’s origins”, the report said.
And allegations that China launched the virus as a bioweapon were dismissed because their proponents “do not have direct access to the Wuhan Institute of Virology” and are making scientifically invalid claims or are accused of spreading disinformation, the report said.
Four agencies within the intelligence community said with low confidence that the virus was initially transmitted from an animal to a human.
A fifth intelligence agency believed with moderate confidence that the first human infection was linked to a lab.
Prior to writing the report, analysts conducted what the report describes as a “Team A/Team B” debate to try to strengthen or weaken each hypothesis.
The report identifies types of data that investigators still want China to provide access to, including records and tissue samples from several markets in Wuhan, including the Huanan Seafood Wholesale Market, Qiyimen Live Animal Market, Dijiao Outdoor Pet Market and others.
Scientists originally believed the virus emerged from animals sold at the Huanan market, which has since been ruled out by some as the origin site.
