Viral The Search for the Origin of COVID-19

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. 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 was 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.

The red flags that Chan & Ridley discuss fall into roughly three categories. First, despite safety measures, accidents can and do happen and adherence to safety procedures in China has been lax both in the field and in the lab. 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. 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. The much-touted furin-cleavage site, unique to SARS-CoV-2 amongst coronaviruses so far, is an example. Inserting and removing these 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 about closely-related viruses they knew of. The mine where some of these were collected has become a heavily guarded state secret and outsiders are prevented from getting near it. The WIV also took offline a large pathogen database with detailed information on thousands of samples collected all over China in the last decade, including some 630 novel coronaviruses. 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.

Viral thus 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 are likely to 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. If this book seems weighted towards the lab leak scenario, it is because the spillover scenario has been the widely accepted, uncontroversial null hypothesis (it was for me). 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 scenario. It is a subtle but important difference. Indeed, I have become less sure with time and Viral reveals many disconcerting red flags to take seriously the possibility of a lab leak.

If there are weak points to this book it is that Chan & Ridley insufficiently explain how the WHO functions and how it is virtually powerless to enforce anything. Furthermore, the authors do not explore the possibility that we might never find a satisfactory answer. 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?

This is hardly going to be the last word on this topic but, in the meantime, if you want to understand why people are arguing about the origin of COVID-19, Viral provides an in-depth and calm look at what we do and do not know.