WHO, China Report Posits Origins of COVID-19 Pandemic

The study states that it is “extremely unlikely” the pandemic virus occurred through a laboratory leak in Wuhan, China.

The coronavirus disease 2019 (COVID-19) pandemic most likely began with a bat infecting another animal with the SARS-CoV-2 virus and that animal in turn transmitting it to a human host, according to a study by the World Health Organization (WHO) and China. The study is scheduled to be officially released tomorrow, but a draft was obtained by the Associated Press.

The findings, which contribute toward an interpretation of COVID-19’s origins, also state that it is “extremely unlikely” the pandemic virus occurred through a laboratory leak—a popular theory held among leadership outside of China at the beginning of the outbreak, and one held by some health experts in the United States, such as Robert Redfield, the former director of the Centers for Disease Control and Prevention (CDC). In talking to CNN, Redfield stressed that this was only his opinion, however.

Redfield said: “It's not unusual for respiratory pathogens that are being worked on in a laboratory to infect the laboratory worker. ... That’s not implying any intentionality. It’s my opinion, right? But I am a virologist. I have spent my life in virology.”

Redfield served under former President Trump. But President Biden’s Secretary of State Anthony J. Blinken indicated last week in an interview with CNN that he’s taking a wait-and-see attitude toward the report, questioning how the data were collected and interpreted.

“We’ve got real concerns about the methodology and the process that went into that report, including the fact that the government in Beijing apparently helped to write it,” Blinken said. “But let’s see what comes out in that report.”

Nevertheless, the WHO report discounts both Redfield’s opinion and Blinken’s misgivings. The report is largely based on a WHO investigator visit to Wuhan from mid-January to mid-February this year. The investigators detailed 4 scenarios by which SARS-CoV-2 could have emerged, listed in order of most likelihood to least:

  • Bats through another animal (very likely)
  • Direct spread from bats to humans (likely)
  • Cold-chain food products (possible but not likely)
  • Laboratory leak (extremely unlikely)

As the report draft explains, the evolutionary distance between bat-based coronaviruses and SARS-CoV-2 is estimated to be several decades, “suggesting a missing link.”

The WHO-led expedition to the original outbreak epicenter, as detailed previously in a podcast by HCPLive and the American Lung Association (ALA), speaks to the gap of knowledge still missing in understanding how the pandemic began, and what means were capable of preventing it.

As Donald Alcendor, PhD, vaccinologist and immunologist from Meharry Medical College and Vanderbilt University School of Medicine, explained in the podcast, the zoological intermediary to human transmission is still just a prediction.

“We know this is a zoological transmission,” Alcendor explained. “We have to understand how this virus is being transmitted in the animals that service reservoirs. And once we do, we need to limit this zoological contact to humans.”

Alcendor’s suggestion that pangolins—better known as scaly anteaters—may be involved in the SARS-CoV-2 human origin was supported by the WHO report, which noted the mammals have been observed with highly similar viruses. The report also suggested that mink and cats could have served as the intermediary, as both species carry COVID-19.

That said, the report did not draw conclusion on the belief that the outbreak began at a Wuhan seafood market—which sold a range of animal products, from bamboo rats and deer, to even live crocodiles—that reported a case cluster in December 2019. Previous cases observed outside the area of the market suggest the outbreak began elsewhere.

“No firm conclusion therefore about the role of the Huanan market in the origin of the outbreak, or how the infection was introduced into the market, can currently be drawn,” investigators wrote.

Peter Ben Embarek, a food scientist and WHO expert leading the Wuhan assessment, told AP on Friday the report was finalized and awaiting public release.

This article originally appeared in Contagion®.