The Washington PostDemocracy Dies in Darkness

Opinion Available evidence still points to covid originating from spillover

The Huanan Wholesale Seafood Market in Wuhan, China, on Jan. 23, 2020. (Dake Kang/AP)
5 min

Angela Rasmussen is a virologist and principal research scientist at the Vaccine and Infectious Disease Organization at the University of Saskatchewan. Saskia Popescu is an infectious-disease epidemiologist and assistant professor of biodefense at the Schar School of Policy and Government at George Mason University.

The news last week that the Energy Department had concluded with “low confidence” that SARS-CoV-2 originated from a “lab leak” caused FBI Director Christopher A. Wray to remind Fox News viewers that his agency reached the same conclusion about the coronavirus in 2021.

No new evidence is available for public scrutiny. It is impossible to evaluate the Energy Department’s claims. Yet they have been repeated in many quarters as if they were proof of a lab origin — a belief that fuels demands to curtail work on dangerous infectious agents.

This circus makes the United States and the world less prepared, not more, to defend itself against emerging pathogens that could lead to pandemics, including the alarming influenza strain H5N1 spreading globally in animals or the deadly Marburg virus outbreak in Equatorial Guinea.

To be clear, all the evidence available for scrutiny points to the pandemic originating from transmission from live animals to humans — zoonotic spillover — at the Huanan Seafood Wholesale Market in Wuhan, China.

Two studies (one co-authored by one of us) published in 2022 in the U.S. journal Science mapped the verifiable earliest cases, environmental samples collected at the Huanan market, records of animal sales at the market, social media data and susceptibility data about the animals. Triangulating all this demonstrated that the pandemic started with two independent spillover events at the market, or just upstream in the common supply chain where the animals were sourced or transported.

The Huanan market is roughly the size of a soccer field. It is about nine miles away — across the Yangtze River — from the Wuhan Institute of Virology, the only lab in that city known to have an active research program on coronaviruses.

No other explanation, including a laboratory origin at the Wuhan Institute or the Wuhan Center for Disease Control and Prevention, is consistent with the existing body of evidence. There have been numerous attempts to challenge the quality of these data and the analysis or to present original research supporting a lab leak. Only one has survived peer review.

The facts cannot be refuted by undisclosed evidence that merited the Energy Department’s low-confidence rating. This bar is cleared by information that is “scant, questionable, fragmented” or information from which “solid analytical conclusions cannot be inferred.”

This focus on labs overlooks the real and enduring biosecurity risk: cities where people and animals live in close contact.

Zoonotic spillover is not rare. Particularly among people working with animals, SARS-like coronaviruses frequently spill over. If a virus has to evolve to replicate efficiently after it jumps species, it might not have the time or opportunity to take hold. But SARS-CoV-2 is a generalist. It can spread efficiently in deer, cats, dogs, minks, monkeys, rodents and a variety of zoo animals, as well as humans. In a rural setting, SARS-CoV-2 spillover might not have spread in humans.

Only in a city with a large, mobile, interactive population of people and animals could the virus establish sustained onward transmission from person to person. This pandemic could have just as easily begun in Beijing, Shanghai or Guangzhou — where SARS-CoV-1 emerged in 2002, also as a direct result of the sale of live animals at “wet markets.”

The key point is not that all these places also have laboratories that study coronaviruses. The key point is that in any city where people and animals dwell cheek by jowl, they exchange viruses. And will do so again.

One thing everyone involved in studying the origins of SARS-CoV-2 seems to agree on — FBI and Energy Department included: No laboratory modification of a virus was involved. Indeed, there has never been an infection reported as a result of a pathogen generated through gain-of-function research.

Gain-of-function and loss-of-function techniques are rarely used with pathogens that have pandemic potential. The techniques make pathogens more or less virulent or transmissible or both. So they must be done in tightly regulated laboratories operating at biosafety level 3 or 4 containment, depending on the virus. The National Science Advisory Board for Biosecurity has recently updated recommendations around such work.

Gain-of-function work has many benefits, despite claims it is all risk and no reward. It is necessary to understand how flu mutates to infect different mammals, us included. Gain-of-function work also showed that the spike protein was crucial for immunity, enabling the development of effective coronavirus vaccines in record time, saving millions of lives.

Deepening partisanship on covid-19 hinders progress at home and abroad. None of the witnesses called so far by the House Select Subcommittee on the Coronavirus Pandemic for its first hearing this week has technical expertise on SARS-CoV-2 origins science. Few have experience within the covid-19 response effort. All have promoted pro-lab leak opinions without providing any evidence to support their claims. It is easier to place blame than to address systemic issues that led to more than a million covid deaths in the United States.

Identifying origins must be foundational in outbreak response. Delays limit the potential for absolute findings, which strains global partnerships crucial to biosecurity.

But the quest should not distract from the larger evaluation of the United States’ woefully inadequate response to covid-19. Crucially, it must not detract from the most pressing priority: defense against future pandemics that might be brewing right now.

Coronavirus: What you need to know

End of the public health emergency: The Biden administration ended the public health emergency for the coronavirus pandemic on May 11, just days after WHO said it would no longer classify the coronavirus pandemic as a public health emergency. Here’s what the end of the covid public health emergency means for you.

Tracking covid cases, deaths: Covid-19 was the fourth leading cause of death in the United States last year with covid deaths dropping 47 percent between 2021 and 2022. See the latest covid numbers in the U.S. and across the world.

The latest on coronavirus boosters: The FDA cleared the way for people who are at least 65 or immune-compromised to receive a second updated booster shot for the coronavirus. Here’s who should get the second covid booster and when.

New covid variant: A new coronavirus subvariant, XBB. 1.16, has been designated as a “variant under monitoring” by the World Health Organization. The latest omicron offshoot is particularly prevalent in India. Here’s what you need to know about Arcturus.

Would we shut down again? What will the United States do the next time a deadly virus comes knocking on the door?

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