Breathless: The Scientific Race to Defeat a Deadly Virus

by David Quammen

Although the point will still be argued, at least by holdouts, until more evidence emerges, these new findings further supported the proposition that SARS-CoV-2 came to humans by way of some direct, catastrophically unfortunate interaction with wild animals.

Nobody knows everything about this virus, and our efforts to comprehend it have only begun. As lengthy as the dreary months and years of the COVID-19 pandemic—the pandemic so far—may have felt to us, the time is early. We’ve scarcely started the effort of adapting ourselves and our societies for its next challenges and later stages. This virus is going to be with us forever. It will be in humans—always somewhere—and it will be in some of the animals that surround us. The rule “Never say never” is a sensible one, but no expert can tell us right now how SARS-CoV-2 might ever be eradicated. We haven’t eradicated polio, despite decades of effort. We haven’t eradicated measles. And those viruses have nowhere to hide except within humans. This virus has many more options. We might clear it from every human on Earth (not likely) and it will still be there in the white-tailed deer of Iowa, the stray mink on the landscape of Denmark.

Did evolutionary selection favor all of Omicron’s significant changes individually, amino acid by amino acid, or did it favor them as a bundle—for their combined effect, their intricate interaction, their collective bottom line? The second of those propositions, as Martin and his coauthors noted, has a fancy name in genetics: positive epistasis. This concept is simple (only the details are complex). Epistasis refers to the interactive effects of genes in different parts of the genome, playing off one another or harmonizing, like instruments in different parts of an orchestra. A mutation inclined to have neutral or even negative impact individually may perform a beneficial function when that gene interacts with others. Further, the effect of one mutated gene may depend on the presence or absence of mutations in other genes. Positive epistasis in the context of Omicron means that multiple mutations are enhancing the adaptive value of one another. This variant, with its many mutations, may be a creature in which great intricacies of epistasis are making it more formidable. Kristian Andersen has a postdoc in his lab, Edyth Parker, who put it more vividly when she said that “the epistatic fucking cirque du soleil of this virus is discombobulating.”

More than fifty years ago, when I first read Faulkner and fell under his spell, the single impression that struck me most, the single bit of wisdom I saw underpinning his tales and the way that he told them, was that the truth of any event or person is fragmented, and those fragments are only available from diverse points of view.