Scientists reconsider accidental lab leak theory as COVID-19 origins remain unclear

The dominant theory of the origins of SARS-CoV-2, the virus that causes COVID-19, has remained virtually unchanged for more than a year: An animal, probably a bat in southwestern China or Southeast Asia, infected another animal that then infected a human, probably in Wuhan, China.

• The location of the original source animal, type of intermediate species, and exact location and timing of “patient zero” are unknown and difficult, perhaps impossible, to pin down.
• A “Phase 1” report from the World Health Organization’s inquiry into the pandemic’s origins, released in March, yielded no profound new insights. The investigators essentially affirmed the dominant theory and said more data was needed.
• However, the WHO director-general, Tedros Adhanom Ghebreyesus, gave unexpected remarks that the report did not conduct “extensive enough” research into the possibility that a lab leak might have been involved.

Earlier this month, a group of 18 scientists agreed with Tedros. Writing in Science Magazine, they criticized the WHO report for devoting “only 4 of [its] 313 pages” to the “possibility of a laboratory accident.” They urged:

We must take hypotheses about both natural and laboratory spillovers seriously until we have sufficient data…Public health agencies and research laboratories alike need to open their records to the public.

One of those scientists is Ralph Baric, a microbiologist at the University of North Carolina, who has worked closely with the Wuhan Institute of Virology — the place that some suspect could have had a lab leak incident.

• “A rigorous investigation would have reviewed the biosafety level under which bat coronavirus research was conducted at WIV,” Baric told the Wall Street Journal, criticizing the limited access that China gave investigators when they visited Wuhan.
• Shí Zhènglì 石正丽, the leading bat coronavirus expert at WIV, has long denied that the genetic sequences of any viruses she studied were similar to the pandemic strain, and insisted that there have been “zero infections” and no lab leaks at WIV.
• Peter Ben Embarek, the WHO team lead, told the WSJ that his understanding is WIV “never succeeded to culture a virus out of the bat feces sample” that it had gathered during research in southwest China — and the genetic code of that sample was very distinct from SARS-CoV-2 anyway.

But several other leading scientists have become more skeptical of WIV in recent months, the WSJ says, including Ian Lipkin, an infectious-disease specialist at Columbia University, and James Le Duc, the former director of the Galveston National Laboratory, a top U.S. biocontainment facility.

• Additionally, while laboratory manipulation of a coronavirus is generally thought to have “clear genetic signatures” — 27 scientists last year wrote it was a “conspiracy theory” to suggest SARS-CoV-2 did not have a natural origin — some scientists disagree and say “more modern techniques can leave no trace.”

The fight over Phase 2 investigation

The next steps in the search for the pandemic’s origins are being hashed out in part this week, at the World Health Assembly. At the WHA, U.S. Health and Human Services Secretary Xavier Becerra “said future studies into the origins of the COVID-19 pandemic needed to be transparent and respect the independence of scientists,” per the SCMP, while China has rejected “fresh calls for consideration of [the] lab leak theory.”

• WHO’s Ben Embarek told the WSJ that his team has recommended “antibody tests and surveys of people and animals” around an abandoned mine in southwest China with bats known to contain a virus most closely related to SARS-CoV-2. But the “timeline is still, still not clear.”

See also:

• Timeline: How the Wuhan lab-leak theory suddenly became credible / Washington Post (paywall)
• Wuhan laboratory adds another branch to bat coronavirus family tree / SCMP (paywall)
• China WHO probe: Coronavirus investigators pinpoint overlooked Chinese data for further study, source says / CNN
  “Previously overlooked Chinese data on extensive screening of animals for coronavirus around the time the pandemic erupted is among several areas identified for further study by World Health Organization (WHO) scientists investigating the origins of COVID-19, a source close to the team told CNN.”