On march 27, as the U.S. topped 100,000 confirmed cases of COVID-19, Donald Trump stood at the lectern of the White House press-briefing room and was asked what he’d say about the pandemic to a child. Amid a meandering answer, Trump remarked, “You can call it a germ, you can call it a flu, you can call it a virus. You know, you can call it many different names. I’m not sure anybody even knows what it is.”
That was neither the most consequential statement from the White House, nor the most egregious. But it was perhaps the most ironic. In a pandemic characterized by extreme uncertainty, one of the few things experts know for sure is the identity of the pathogen responsible: a virus called SARS-CoV-2 that is closely related to the original SARS virus. Both are members of the coronavirus family, which is entirely distinct from the family that includes influenza viruses. Scientists know the shape of proteins on the new coronavirus’s surface down to the position of individual atoms. Give me two hours, and I can do a dramatic reading of its entire genome.
But much else about the pandemic is still maddeningly unclear. Why do some people get really sick, but others do not? Are the models too optimistic or too pessimistic? Exactly how transmissible and deadly is the virus? How many people have actually been infected? How long must social restrictions go on for? Why are so many questions still unanswered?
The confusion partly arises from the pandemic’s scale and pace. Worldwide, at least 3.1 million people have been infected in less than four months. Economies have nose-dived. Societies have paused. In most people’s living memory, no crisis has caused so much upheaval so broadly and so quickly. “We’ve never faced a pandemic like this before, so we don’t know what is likely to happen or what would have happened,” says Zoë McLaren, a health-policy professor at the University of Maryland at Baltimore County. “That makes it even more difficult in terms of the uncertainty.”
But beyond its vast scope and sui generis nature, there are other reasons the pandemic continues to be so befuddling—a slew of forces scientific and societal, epidemiological and epistemological. What follows is an analysis of those forces, and a guide to making sense of a problem that is now too big for any one person to fully comprehend.
I. The Virus
Because coronavirus wasn’t part of the popular lexicon until SARS-CoV-2 ran amok this year, earlier instances of the term are readily misconstrued. When people learned about a meeting in which global leaders role-played through a fictional coronavirus pandemic, some wrongly argued that the actual pandemic had been planned. When people noticed mentions of “human coronavirus” on old cleaning products, some wrongly assumed that manufacturers had somehow received advance warning.
There isn’t just one coronavirus. Besides SARS-CoV-2, six others are known to infect humans—four are mild and common, causing a third of colds, while two are rare but severe, causing MERS and the original SARS. But scientists have also identified about 500 other coronaviruses among China’s many bat species. “There will be many more—I think it’s safe to say tens of thousands,” says Peter Daszak of the EcoHealth Alliance, who has led that work. Laboratory experiments show that some of these new viruses could potentially infect humans. SARS-CoV-2 likely came from a bat, too.
It seems unlikely that a random bat virus should somehow jump into a susceptible human. But when you consider millions of people, in regular contact with millions of bats, which carry tens of thousands of new viruses, vanishingly improbable events become probable ones. In 2015, Daszak’s team found that 3 percent of people from four Chinese villages that are close to bat caves had antibodies that indicated a previous encounter with SARS-like coronaviruses. “Bats fly out every night over their houses. Some of them shelter from rain in caves, or collect guano for fertilizer,” Daszak says. “If you extrapolate up to the rural population, across the region where the bats that carry these viruses live, you’re talking 1 [million] to 7 million people a year exposed.” Most of these infections likely go nowhere. It takes just one to trigger an epidemic.
Once that happens, uncertainties abound as scientists race to characterize the new pathogen. That task is always hard, but especially so when the pathogen is a coronavirus. “They’re very hard to work with; they don’t grow very well in cell cultures; and it’s been hard to get funding,” says Vineet Menachery of the University of Texas Medical Branch. He is one of just a few dozen virologists in the world who specialize in coronaviruses, which have attracted comparatively little attention compared with more prominent threats like flu. The field swelled slightly after the SARS epidemic of 2003, but then shrunk as interest and funding dwindled. “It wasn’t ’til MERS came along [in 2012] that I even thought I could have an academic career on coronaviruses,” Menachery says.
The tight group of coronavirologists is now racing to make up for years of absent research—a tall order in the middle of a pandemic. “We’re working as hard as possible,” says Lisa Gralinski, a virologist at the University of North Carolina. “Our space is so intermingled that we can’t socially distance among ourselves much.”
One small mercy, she notes, is that SARS-CoV-2 isn’t changing dramatically. Scientists are tracking its evolution in real time, and despite some hype about the existence of different strains, the virologists I’ve spoken with largely feel that the virus is changing at a steady and predictable pace. There are no signs of “an alarming mutation we need to be worried about,” Gralinski says. For now, the world is facing just one threat. But that threat can manifest in many ways.
II. The Disease