Amid a muddled quest for COVID’s source, a crucial message
Pandemics might seem to strike out of the blue, but they don’t come from nowhere. New infectious diseases in humans tend to arise from other animals through “spillover events,” but outbreaks can also occur when pathogens escape the laboratories where they are being studied. For this reason, the nagging fact that the earliest known coronavirus cases occurred in the Chinese city of Wuhan, which happens to be home to the Wuhan Institute of Virology, has seemed a striking coincidence at best and suspicious at worst.
The unknown origins of the pandemic are the subject of Alina Chan and Matt Ridley’s book, “Viral.” The topic is of extraordinary importance and deserves a thorough, careful investigation, aided by government transparency and explanation of the science involved. Unfortunately, when it comes to cooperation with independent investigators, the Chinese authorities have been about as transparent as a lead window, leaving facts thin on the ground. Chan and Ridley make up for this by stretching some of the facts that we do have beyond what they should bear. This diminishes the impact of a book that closes with an important message.
The authors start with the viruses that are the closest known relatives of the coronavirus known as SARS-CoV-2. These originate from an investigation of a 2012 outbreak in a mine many miles from Wuhan, of an illness much more severe than most COVID-19 cases, from which a coronavirus was isolated and its genome sequenced. Years later, that sequence turned out be 96 percent identical to that of the virus that erupted in late 2019 around a market in Wuhan. To the casual observer, this seems highly suggestive. Chan and Ridley certainly present it as such, as the 96 percent figure is repeated again and again, standing for itself as a vital piece of evidence without scientific context to imply a link between the outbreak, the lab and the pandemic.
The problem is that for someone who knows about evolution, 96 percent identical is not very closely related. In fact, it’s really quite different. It means the genomes are different in more than 1,000 places, whereas if these other viruses really were tightly linked to SARS-CoV-2, we’d expect a handful. For comparison, they’re about as closely related as you are to a chimpanzee. Viruses accumulate changes more quickly than we do, but even so, the pandemic and this outbreak are clearly separated by years or decades of independent evolution outside a lab. The book does not mention this inconvenient fact, among many others.
One of the things a good professional scientist does is take his or her cherished hypothesis and try to break it every which way, by conducting experiments or hunting for data that does not agree with it. This is a way to avoid confirmation bias, the natural human tendency to hear what we want to hear and disregard the rest. A key property of scientific theories is that they can be proved wrong. Unfortunately, it is hard to imagine such evidence that would convince strong partisans of either laboratory or natural origins. And too much of “Viral” is made up of confirmation bias. Nobody should mistake this book for an evenhanded scientific document.