10-minute read

From the start of the COVID-19 pandemic, the origin of the SARS-CoV-2 virus has been one of the big questions. The default assumption for many has been zoonosis: a natural spillover event where an infectious disease jumps from an animal host into the human population. But could it have escaped from one of the several virology laboratories in Wuhan? Initially cast aside as a conspiracy theory, the idea has slowly been gaining credibility. Viral is a disconcerting book that considers what we know so far. Though the smoking gun remains missing, the circumstantial evidence raises several red flags. Given the increasingly heated and polarised discussion around this topic, I started reviewing this book with some trepidation.

Alina Chan, a molecular biology postdoc who has consistently argued that we lack the information to exclude either explanation, is co-authoring this book with Matt Ridley, the biologist-turned-journalist-turned-businessman and author of Genome. Now, before delving into the details, two quick observations. One is what this book is not. In all the hubbub, the idea of an accidental lab leak has become conflated with that of a deliberately engineered bioweapon—and before you know you are indeed in crackpot-territory. The authors think that “allegations that SARS-CoV-2 is a bioweapon or a vaccine trial that went wrong are a distraction” (p. 201). This book is also not about assigning blame but about understanding where this virus came from so we can better prepare for the next one—whether by addressing illegal wildlife trafficking or revising best practices in laboratories. Two is that, though the book is well written, things inevitably get technical in later chapters. Readers without a background in genetics and molecular biology might struggle with some of the material here.

The first few chapters get you up to speed on virology basics, the history of research on coronaviruses, and the early developments in Wuhan. It clarifies that the default position of zoonosis is entirely reasonable. After all, the 2003 SARS epidemic started as an outbreak via animals sold in wildlife markets. Then there was the early red herring of pangolins. These are poached for their scales that are an ingredient in traditional Chinese medicine. Researchers initially thought they had found a pangolin virus closely matching SARS-CoV-2, but further study disproved this. Furthermore, pangolins are not great hosts for a respiratory virus, living mostly solitary lives. Bats, however, are a different story.

Two important parties are also introduced: the Wuhan Institute of Virology (WIV), led by Shi Zhengli, and the US-based NGO EcoHealth Alliance (EHA), led by Peter Daszak. The WIV is a leader in research on bat coronaviruses and, with financial support from the EHA, has sampled thousands of bats inside and outside of China*. They have compiled a comprehensive virus database and done experiments to increase our understanding of how these viruses attack the human body. This is important and well-intentioned pathogen research that could lead to the development of broad-spectrum vaccines against coronaviruses and, hopefully, the prediction and prevention of future outbreaks. Look out for the upcoming book The Invisible Siege which will go into much more detail on research by Ralph Baric’s team who worked with Shi Zhengli and the WIV. That said, pathogen research is not without its risks, nor its detractors.

“This is important and well-intentioned pathogen research that could lead to the development of broad-spectrum vaccines against coronaviruses [but it] is not without its risks, nor its detractors.”

The red flags that Chan & Ridley discuss fall into roughly three categories. First, despite safety measures, accidents can and do happen and they review some notable examples. Adherence to safety procedures in China has been lax: fieldworkers handling bats do not always wear appropriate gear while US officials inspecting the WIV noted a lack of trained technicians. Another Wuhan lab was looking for a new waste disposal contractor, admitting that hazardous waste had “not been effectively treated from 1994 to 2019“. And new national biosafety rules in 2020 were aimed at closing such loopholes as “scientists selling the animals used in laboratory experiments for profit” (p. 165).

Second are details relating to the virus itself, which is easily the most technical material in this book. While the SARS virus quickly evolved when it first emerged in humans, SARS-CoV-2 seemed well-adapted to us and remained surprisingly stable genetically (though new variants have since evolved). There is a trail of published research showing that in recent years virologists have become very good at modifying SARS-like coronaviruses, including gain-of-function research where you give the virus an evolutionary helping hand to better understand how infection works. One bone of contention is a short amino acid sequence in SARS-CoV-2 (a furin cleavage site) that recruits an enzyme (furin) to help the virus gain access to cells. A typical example of a virus cleverly turning our cellular machinery against us. “Furin cleavage is a big reason that SARS-CoV-2 has such pandemic potential” (p. 206). This sequence has so far not been found in wild coronaviruses, leading some people to conclude it is proof of genetic engineering. This may seem a silly argument, reminiscent of creationists saying that the perfection of certain features can only mean they were (intelligently) designed. Until you realise that inserting and removing furin cleavage sites has become a routine procedure in virology and was done at the WIV.

Finally, there is the behaviour of China and some of the researchers involved. The WIV and Shi have held back important information. They published the genetic sequence of SARS-CoV-2 but left out the part showing the furin cleavage site, despite Shi’s previous research on its importance. They published on a closely-related virus but failed to mention it was collected from a mine where several workers had fallen ill and died of a mysterious disease in 2012. In actual fact, they belatedly revealed finding eight more SARS-like coronaviruses here. The mine has since become a heavily guarded state secret and outsiders are prevented from getting near it. The WIV had a large pathogen database with detailed information on thousands of samples collected all over China in the last decade, including some 630 novel coronaviruses. This database was taken offline in September 2019 and has never been shared since, with both the WIV and the EHA refusing to discuss the matter. And finally, there was the heavily orchestrated and unsatisfactory visit by the World Health Organization (WHO) to Wuhan in 2021 that came to the unlikely conclusion of infection via the frozen food chain.

“If this book seems weighted towards the lab leak scenario, it is because the spillover scenario has been the widely accepted, uncontroversial null hypothesis.”

Many of these findings only came to light thanks to the unrelenting sleuthing of a motley crew of (anonymous) amateurs, later joined by several scientists, that goes by the acronym of DRASTIC. This might raise some eyebrows. Why not involve actual virologists? Because most of them publicly labelled the lab leak a conspiracy theory, e.g. in a letter to The Lancet that Daszak organised without declaring so. Farrar mentioned in Spike that many virologists were less sure in private. More pertinent is that, on several occasions, DRASTIC’s work forced the hand of the WIV to publicly or surreptitiously release more information, confirming what they had already puzzled out. The acknowledgements mention that Shi, Daszak, and several others were given the opportunity to comment on their portrayal in this book, but did not respond.

Viral has so far garnered mixed reviews, with e.g. The Guardian and The New Republic slating the book for pretending to be agnostic and impartial. These journalists fall back on the tired trope of questioning Ridley’s integrity by pointing out his climate change scepticism. Though I disagree with Ridley on this particular matter, I fail to see the relevance: it does not mean that everything he says is rubbish. Meanwhile, before Viral was published, Chan was one of the scientists tearing apart the paper of a Chinese whistleblower that claimed SARS-CoV-2 was a bioweapon. Call me naïve, but I see no reason to suspect the authors of duplicitous motives. Thomas Levinson, writing in Nautilus, argued that it is not enough to say that accidents happen, but to establish what happened. Fair point, but that requires that we consider it a realistic possibility. This is the whole point of Viral. If this book seems weighted towards the lab leak scenario, it is because the spillover scenario has been the widely accepted, uncontroversial null hypothesis, even though there is little evidence to back it up either. The goal here is not to prove either scenario, but to move the needle of the debate from rejecting the lab leak as a conspiracy theory to acknowledging that, at the moment, we cannot firmly reject or accept either explanation. This is a subtle but important difference that seems lost on some commentators.

But enough of other people’s opinions, what do I make of this book? Viral ends up being the written equivalent of a Rorschach test: you can read into it what you like. Those inclined to conspiracy theories will find plenty to say “told you so”. If, like me, you are on the fence, you will likely stay there. And those who disavow the lab leak scenario might judge the book one big nothing-burger that fails to convince. This, by the way, is not a criticism of the authors. This, as they patiently show here, is the current state of play. When the pandemic started, my gut instinct was to assume zoonosis (I even reviewed Quammen’s Spillover and sent a copy to my mum), but picking favourites is not how science works. With time, I have become less sure. Viral confirms that, though there is no solid evidence in favour of either scenario, there are many disconcerting red flags to take seriously the possibility of a lab leak.

“Viral confirms that, though there is no solid evidence in favour of either scenario, there are many disconcerting red flags to take seriously the possibility of a lab leak.”

If there are weak points in this book it is that Chan & Ridley insufficiently explain how the WHO functions and how it is virtually powerless to enforce anything (something MacKenzie explained better in COVID-19). Furthermore, the authors do not explore the possibility that we might never find a satisfactory answer. Whether lab leak or spillover, there has been plenty of time to destroy crucial evidence if somebody wanted to cover up their tracks. Will another enquiry really get to the bottom of this? And what counts as satisfactory evidence?

Viral was published only six weeks after What Really Happened In Wuhan. I suspect that thanks to Chan’s involvement, Viral is stronger on the technical coverage. And this is hardly going to be the last word on this topic, David Quammen’s book Breathless was published in October 2022. I will be following further developments with much interest. In the meantime, if you want to understand why people are arguing about the origin of COVID-19, Viral provides an in-depth and measured look at what we do and do not know.

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* Including, yes, Laos. After the publication of Viral, some journalists touted the finding of the closest match yet to SARS-CoV-2 in Laos bats as undermining the book’s central premise. Except that, as Ridley explains in this extensive interview, the WIV also sampled bats here.

Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.

Chan & Ridley’s Viral

Other recommended books mentioned in this review:

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