Covid-19 is the first pandemic in which molecular genomics has been applied at scale. Thanks to this science, researchers were able to publish the genome of the novel coronavirus, Sars-CoV-2, in record time and keep pace with the emergence of new variants. And thanks to the allied science of molecular phylogenetics, a method for reading the deep evolutionary history of viruses, we have been able to trace its divergence from other known coronaviruses, including other Sars-like coronaviruses harboured by bats and whose genetic codes are stored in labs in China and other parts of the world.
Few writers are able to understand the strings of amino acids that give these viruses their distinctive codes, let alone relate them to other Sars-like viruses. And even fewer possess the literary gifts necessary to make the genomics comprehensible to lay readers. Fortunately, David Quammen, whose previous works include books on Ebola and other viruses that periodically infect humans, is one of them.
As with Spillover, his 2012 bestseller about the risks posed by coronaviruses and other viruses harboured by wild animals, Quammen always has a literary reference to hand when the science gets difficult. Thus, we learn that the genetic codes of viruses are no more viruses than the play Hamlet is a performance. In literary terms, they are merely texts. It takes several more steps, including culturing them in animal cells, to make them strut the world’s stage. And it takes a process known as “gain of function” to convert them into the genomic equivalent of Frankenstein’s monster.
This is important because from the beginning of the coronavirus pandemic, the origins of Sars-CoV-2 have been the subject of feverish debate: was it the result of a natural spillover from animals or was the virus engineered in a lab and unleashed upon the world, either by accident or design?
Exhibit one in the latter theory is the recovery, prior to the pandemic, of a viral sequence, labelled RaTG13, reconstructed by Chinese researchers from bat shit recovered in 2013 from a cave near Kunming, in Yunnan. That bat shit was brought to the Wuhan Institute for Virology (WIV) where scientists succeeded in growing live virus from it. To date, that virus is the closest genetic match for Sars-CoV-2, and since Kunming is 1,300 miles from Wuhan as the bat flies, suspicion has fallen on Chinese scientists.
Breathless does not address those suspicions right away. Instead, in 390 pages encompassing 76 chapters, Quammen takes us on a whistlestop tour from Wuhan to Washington DC, via labs and researchers in cities as diverse as Hong Kong, Sydney, Edinburgh, Rotterdam and New Orleans. Although most of the interviews for this book were conducted via Zoom, Quammen has previously tramped through jungles in south-east Asia and visited caves with many of the scientists who feature in his pages. This not only allows him to leaven the science with vivid pen portraits but makes him a shrewd judge of character. What emerges is a viral howdunnit that is pacy and unafraid to educate readers in the nuances of gain of function and the wider ecology of pandemics without straying into invective.
We will probably never know the origins of the pandemic, says Quammen. This is partly because samples from animals traded at the Huanan “wet market” in Wuhan, likely to have been the centre of the pandemic, and other live animal markets in China that are suspected of harbouring the virus were not collected in a timely manner. But it is also because science is never settled and experts qualified to read the genome of Sars-CoV-2, and other viruses to which it bears a close resemblance, disagree (on this, Quammen is characteristically modest, comparing his own expertise to looking through “a long, blurry, turned-around telescope of ignorance”).
There is not the space in this review to revisit the questions made familiar by conspiracy theorists as to why some prominent scientists initially withheld their suspicions that the virus may have been engineered in WIV or why some experts believe certain features of the virus are “unusual” and could not have emerged through natural selection. Suffice to say, Quammen addresses each theory and concern in exemplary fashion.
To take one example: examining the claim of Alina Chan, a Boston-based researcher, that when Sars-CoV-2 was first detected in Wuhan it was already “well adapted to its human host”, something that to her suggests laboratory manipulation, Quammen states: “True fact.” However, he quickly adds that the key question is whether the virus was “inexplicably, suspiciously and uniquely human-adapted”?
I don’t think I’m giving too much away in saying that Quammen does not think this particularly suspicious, given that Sars-CoV-2 is a generalist virus, capable of infecting a wide range of animals, including bats, pangolins, cats, mink and white-tailed deer. He also points out it has evolved considerably since (think Omicron).
But perhaps the real value of this book is that Quammen brings a naturalist’s eye to these debates. At the end, one is left with a deep appreciation of the diversity of nature and the serendipity of natural selection, which every day is shuffling and rearranging the genomes of viruses in ways that scientists can only begin to imagine.
And for all that molecular genomics and gain of function experiments risk accidentally creating something new to nature, they are also our best chance of anticipating and preparing our defences for the next pandemic.
Breathless: The Scientific Race to Defeat a Deadly Virus by David Quammen is published by Bodley Head (£20). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply
