The coronavirus wasn’t made in a lab. So why does the ‘Yan report’ say it was?

Twenty years ago, data scientist Sinan Aral began to see the formation of a trend that now defines our social media era: how quickly untrue information spreads. He watched as false news ignited online discourse like a small spark that kindles into a massive blaze. Now the director of the MIT Initiative on the Digital Economy, Aral believes that a concept he calls the novelty hypothesis demonstrates this almost unstoppable viral contagion of false news.

“Human attention is drawn to novelty, to things that are new and unexpected,” says Aral. “We gain in status when we share novel information because it looks like we’re in the know, or that we have access to inside information.”

Enter the Yan report. On September 14, an article was posted to Zenodo, an open-access site for sharing research papers, which claimed that genetic evidence showed that the SARS-CoV-2 coronavirus was made in a lab, rather than emerging through natural spillover from animals. The 26-page paper, led by Chinese virologist Li-Meng Yan, a postdoctoral researcher who left Hong Kong University, has not undergone peer review and asserts that this evidence of genetic engineering has been “censored” in the scientific journals. (National Geographic contacted Yan and the report’s three other authors for comment but received no reply.)

A Twitter firestorm promptly erupted. Prominent virologists, such as Kristian Andersen from Scripps Research and Carl Bergstrom from University of Washington, took to the internet and called out the paper for being unscientific. Chief among their complaints was that the report ignored the vast body of published literature regarding what is known about how coronaviruses circulate in wild animal populations and the tendency to spill over into humans, including recent publications about the origins of SARS-CoV-2.

The experts also pointed out that the report whipped up wild conspiracy theories and wrongly accused academic journals of plotting with conspirators by censoring important evidence.

In July, David Robertson, a viral genomics researcher at University of Glasgow, authored a peer-reviewed paper in Nature Medicine that showed the lineage behind SARS-CoV-2 and its closest known ancestor, a virus called RaTG13, have been circulating in bat populations for decades. Virologists think this relative, which is 96-percent identical to the novel coronavirus, probably propagated and evolved in bats or human hosts and then went undetected for about 20 years before adapting its current form and causing the ongoing pandemic.

The Yan report claims this hypothesis is controversial, and that RaTG13 was also engineered in a lab. But that flies in the face of the overwhelming body of genetic evidence published about SARS-CoV-2 and its progenitors. What’s more, the report was funded by the Rule of Law Society, a nonprofit organization founded by former chief White House strategist Steve Bannon, who has since been arrested for fraud. That’s yet another reason many virologists are questioning the veracity of its claims.

“It’s encroaching on pseudoscience, really,” says Robertson. “This paper just cherry-picked a couple of examples, excluded evidence, and came up with a ridiculous scenario.”

National Geographic reached out to other prominent virologists and misinformation researchers to better understand where the Yan report came from and what it got wrong. Along the way, they offered tips for overcoming misinformation surrounding the coronavirus.

Coronaviruses exist in nature and can infect many different creatures. SARS-like coronaviruses are found in bats, pigs, cats, and ferrets, to name a few. The most widely agreed upon origin of SARS-CoV-2, based on its genetics, is that its ancestors moved around in wild animals—swapping genetic features as they went along—before they jumped into humans.

Scientists have yet to find the direct parent of SARS-CoV-2 in feral beasts, though its closest relatives exist in bats. The virus may have passed through an intermediate animal—pangolins have been implicated—and then evolved to become better at infecting humans. Or it may have made the jump directly from bats to humans, given past examples of such occurrences. After the original SARS outbreak in China 20 years ago, researchers began surveying wild bats in local caves and the people who live near them. A 2018 study found the genetic relatives of the original SARS virus in the winged mammals—as well as specific antibodies, a residual sign of infection, in their human neighbors.

Finding answers to the precise events that led to a spillover pandemic is a “needle in a haystack proposition,” says Ian Lipkin, an epidemiologist from Columbia University, who co-authored an early research paper in Nature Medicine about the natural origins of SARS-CoV-2. The Yan report claims this Nature Medicine report had a “conflict of interest” due to Lipkin’s work in containing the 2002-2003 SARS epidemic, for which he received an award from the Chinese government. Lipkin says this accusation is “absurd,” and when asked for his view on the role of bioengineering in the origins of SARS-CoV-2, he adds, “There is no data to support this.”

Uncovering the natural source of the coronavirus will likely require large-scale sampling of animals—including bat and human populations—in China to trace the evolution of the novel coronavirus. The World Health Organization is readying a team to conduct such an investigation in China, though a timetable has not been released.

The Yan report attempts to tackle this question in a different way, starting with the murky claim that SARS-CoV-2 is bad at infecting bats, therefore it could not have come from them. But scientists point out that viruses are constantly evolving and passing between species. The initial spillover from bats to humans could have happened decades ago, allowing the virus ample time for its spike protein, the part it uses to enter cells, to optimize through natural selection to infect humans.

Another argument made by the Yan report centers on the presence of a “furin-cleavage site” on the spike protein, a critical genetic feature that is thought to enhance the virus’s ability to enter cells. The report claims this feature is found on no other coronavirus and therefore must be engineered. But this statement contradicts findings: similar cleavage sites are found on bat coronaviruses in wild populations.

“I’m going to scream if I have to explain the fact that many viruses have cleavage sites,” says Angela Rasmussen, a virologist at Columbia University.

The report also asserts that SARS-CoV-2 is “suspiciously” similar to two strains of bat coronaviruses, called ZC45 and ZXC21, that were discovered by scientists at military labs in China. The authors claim these strains could have been used as a template to clone a deadlier virus. But other scientists balk at this idea.

First, the two strains differ by as much as 3,500 nucleotide base pairs, the chemical “letters” used in genetic code. As such, they would be a poor starting point for bioengineering SARS-CoV-2. Engineering a virus in which you had to replace more than 10 percent of its genome is inefficient, if not impossible, according to Rasmussen and several other virologists. The fact that these strains were identified at a Chinese military lab is also “just circumstantial,” says Robertson. The bat coronaviruses were circulating in wild bats and could have been discovered by anyone.

The report also argues that SARS-CoV-2 has “restriction-enzyme sites,” or genetic sequences that can be cut and manipulated by enzymes. These genomic features are sometimes used in cloning, and the report claims their presence is indicative of an engineered virus. But scientists point out these sites naturally occur in all types of genomes, from bacteria to humans.

“It looks legitimate because they use a lot of technical jargon. But in reality, a lot of what they’re saying doesn’t really make any sense,” says Rasmussen. She adds that the type of cloning that uses restriction enzymes is very outdated, and so it is unlikely to be used to make a viral bioweapon. And on a basic level, making an engineered virus is not a trivial matter. Scientists are still just trying to understand the molecular and genetic reasons why some viruses are more infectious than others. Adding features to a virus to make it more transmissible, for example, is called gain-of-function research. It is highly controversial for its potential to make bioweapons and was even banned in the U.S. for a time, limiting the data available on how it works.

A hallmark of the pandemic has been a rapid influx of research and free sharing of information to increase the pace of discovery. This practice of posting “preprints”—reports that haven’t been reviewed by academic peers—has its advantages.

“For the scientific community [it] has been very useful,” says Robertson, since more researchers can quickly analyze the available data. But preprints have a dark side too. Misinformation has been another hallmark of the pandemic, and preprints have played a role in fueling news coverage of unproven claims, including the virus mutating into a more deadly form, coming from snakes, or being less deadly than it truly is.

“It can be very hard to disentangle when that’s real news and when it’s not news,” he says, citing the fact that even some peer-reviewed papers on coronavirus have made errors in the rush to publish. This mixture of honest mistakes and insidious ones may just be indicative of a larger trend with publishing during a rapidly evolving crisis.

“I don’t think the preprint system is being weaponized so much as all channels of information are being used to disseminate misinformation: everything from social media to manipulating the mainstream media to preprints to peer-reviewed journals,” says Rasmussen.

Despite the objections of experts, the Yan report and other similar instances of coronavirus misformation, such as the Plandemic documentary, have gained traction on social media because they take advantage of vulnerable human emotions. Those feelings can drive the viral spread of hoaxes

Back in 2018, Aral and his team at the MIT Media Lab put their novelty hypothesis to the test by analyzing 11 years of data from Twitter, or about 4.5 million tweets. Their calculations showed a surprising correlation: “What we found was that false news traveled farther, faster, deeper, and more broadly than the truth in every category of information that we studied, sometimes by an order of magnitude,” Aral explains.

More is at play than just novelty, as Aral discusses in his new book The Hype Machine. The way people react to emotional stories on social media is intense and predictable. Vitriol fills the replies, and false news then becomes 70 percent more likely to be retweeted than the truth.

A complicated combination of psychological factors is at work whenever a reader decides to share news, and otherwise smart people can become part of the cycle of disinformation.

One factor is knowledge neglect: “when people fail to retrieve and apply previously stored knowledge appropriately into a current situation,” according to Lisa Fazio, an assistant professor of psychology and human development at Vanderbilt University.

The human brain seeks out easy options. Readers cut corners, often sharing stories with grabby headlines before looking deeper into the story itself. Even when social media users do read what they share, their rational mind finds other ways to slack off.

For instance, humans are prone to confirmation bias, a way of interpreting new information as a validation of one’s preconceived notions. Motivated reasoning switches on too, and the brain tries to force these new conceptual puzzle pieces together, making connections even when they don’t fit.

The most potent factor that warps critical thinking is the illusory truth effect, which Fazio defines with this scenario: “If you hear something twice, you’re more likely to think that it’s true than if you’ve only heard it once.” So prevalence turbocharges false news, and echo chambers then turn into self-perpetuating whirlwinds of misbelief.

If the news involves politics, it gets yet another virality boost. “Political news travels faster than the rest of false news,” says Aral. “We can speculate that it’s such a lightning rod because it’s so emotionally charged.” And to Aral, the Yan report has every attribute of a false news story that was primed to go viral.

“In terms of that specific story, I would say all of these analyses of why false news spreads apply,” Aral explains. “It’s shocking; it’s salacious. It’s immediately relevant to political debates that are happening, but obviously coronavirus is on everyone’s mind. Trying to understand its origins is a big story.”