A mystery has long surrounded the Great Influenza of 1918-19. Why did a pandemic that killed upward of 50 million people, many of them otherwise healthy young adults, leave such a limited imprint on humanity’s cultural memory — especially in contrast to World War I, which killed less than half as many people? Countless novels and films and monuments investigate or commemorate the trauma that the Great War inflicted on modern consciousness, but the Great Influenza, having torn a deadly path around the world for two years, seemed to be forgotten nearly overnight.
Perhaps the best explanation stems from the century of progress that separates us from its victims. Most of the people alive during the 1918 outbreak were born during the 19th century, when death from infections was tragically familiar, when losing a third of your children to disease was the norm. To them, the mechanized carnage of World War I, with its fighter planes, machine guns and chemical weapons, was a step change in the history of human violence. A terrible flu virus sweeping through your town and killing some of your friends and family — in an age when it was much more difficult to perceive how global the outbreak was, given the limited scope of most news coverage — didn’t seem all that novel an experience by comparison.
We are not likely to experience the same cultural amnesia with Covid-19. The global population that encountered the SARS-CoV-2 virus had grown accustomed to a world where the burden of infectious disease has been greatly reduced. Before Covid, the most terrifying and deadly new virus to attack the United States was H.I.V., which managed to kill 100,000 Americans in its first eight years of spread here. Covid pulled off the same gruesome feat in four months. You could make the case that Covid will prove to be the true “great war” of the early 21st century — the source of so many genuinely new and terrifying experiences, seared into our collective memory: the hauntingly empty streets of Manhattan and Madrid, the corpses stacked in temporary freezers. Decades from now I suspect I will still be able to conjure the backdrop of incessant sirens in Brooklyn in late March 2020, the creeping terror of it all, the dreadful urgency of trying to make decisions to keep your family safe when so little was understood about the nature of the virus itself.
Whatever is coming next — and let’s hope it is a relatively untraumatic descent, with Covid becoming a manageable if endemic disease, no worse than the flu — this particular plague is going to leave a profound legacy.
Which then raises the question: What will that legacy be? There are many examples of mass tragedies that inspired meaningful reforms or scientific breakthroughs — steps forward in human progress that, in the end, most likely saved more lives than the original tragedy claimed. The deadly concentration of the 1854 cholera epidemic in London enabled John Snow to prove that cholera was a disease caused by contaminated water, even though the bacterium itself hadn’t been identified yet; Snow’s insight probably prevented tens of thousands of deaths in the decades that followed. The occupational safety regulations put in place after the Triangle Shirtwaist factory fire in 1911 undoubtedly saved more lives than the 146 lost in that tragedy.
Of course, for meaningful lessons to be learned from a tragedy — whether a factory fire or a pandemic — you have to begin by acknowledging the facts of the event itself. The rise of Covid denialism, in America and elsewhere, is often taken as a reason to doubt that any progress will grow out of the tragedy of Covid-19. But as depressing as anti-science belligerence can sometimes be, there is abundant evidence that we are learning from this epidemic. To begin with, the period from March 2020 to May 2020 almost certainly marked the most significant short-term change ever in worldwide human behavior. Vast sections of the planet effectively froze in place for a few months, and then adopted, en masse, a whole new set of routines to flatten the curve and slow the spread — a genuinely new trick for Homo sapiens. It was not obvious in advance that such a thing was even possible.
Imagine, if you can bear it, what happens the next time word emerges of a novel virus devastating a midsize city somewhere in the world. The slow-motion reaction that characterized the global response to the news from Wuhan in early 2020 would be radically accelerated. Even without public-health mandates, a significant part of the world’s population, particularly in cosmopolitan cities that were hit hard in the early days of Covid, would instantly mask up; where possible, workers would switch back to Zoom; unnecessary travel would cease. No doubt some portion of the population would play down the magnitude of the threat or invent a preposterous conspiracy theory to explain it. But a meaningful number of people would switch back into the “pandemic mode” they learned in 2020-21.
Think about how Covid might have been different if, say, 50 percent of the world’s urban population had switched into this mode on Feb. 1, 2020. Could this have stopped the virus in its tracks? Perhaps not. But it might have resulted in a global outbreak that looked more like South Korea’s experience, or San Francisco’s, with death rates a tiny fraction of what they ultimately proved to be.
We are learning from Covid in a more obvious way as well: through the lens of science. After the Great Influenza, it took 13 years — thanks to a young virologist named Richard Edwin Shope, who noticed veterinary reports about an unusual outbreak of swine flu among pigs in fall 1918 — to prove that the pandemic had been caused by a virus at all. The contrast with Covid could not be more extreme: We isolated the SARS-CoV-2 virus about 20 days after the outbreak was first reported. Just over a week later, its genome had been sequenced and shared around the world, and the blueprint for what would become the mRNA vaccines (the ones manufactured, ultimately, by Pfizer and Moderna) was essentially complete.
It’s important to remember that mRNA vaccines were a promising, if unproven, line of inquiry for years before the pandemic hit; no one could say for sure that they even worked. But now BioNTech has announced that it’s ramping up development of a malaria vaccine using messenger RNA as the delivery mechanism, and Moderna and partners announced that they’re beginning trials of two mRNA candidate vaccines against H.I.V. Malaria kills roughly 400,000 people a year, H.I.V. nearly a million, and both diseases disproportionately affect the young. If the successful mass rollout of the Covid vaccines winds up accelerating the timeline for these other vaccines, the impact on human life will be enormous.
And just as the Great Influenza slowly nudged scientists toward the development of flu shots, which finally became commonplace in the 1940s, the Covid crisis will redirect vast sums of research dollars toward the development of universal vaccines to protect against all variants of both influenza and coronavirus. Given the relentless, year-in-and-year-out disease burden of flu around the world, a vaccine that reduced its virulence by an order of magnitude would be a life saver of historic proportions.
What about the more subtle psychological legacy of Covid? How will it change the way we perceive the world — and its risks — when the pandemic finally subsides? I have a memory from May of this year, taking my 17-year-old son to the Javits Center in Manhattan for his first vaccine, followed by a shopping trip to pick out a tie for his (masked, outdoor) senior prom. At some point waiting in line, I made a halfhearted joke about how we were embarking on the classic father-son ritual of heading out to the mass vaccination site to protect him from the plague. I meant it ironically, but the truth is that for my son’s generation, proms and plagues will be part of the rituals of growing up.
There is a loss of innocence in that, but also a hard-earned realism: the knowledge that rare high-risk events like pandemics are not just theoretically possible but likely, in an increasingly urban and interconnected world of nearly eight billion people. As a parent, you want to protect your children from unnecessary anxieties, but not when the threat in question is a real one. My son’s generation will forever take pandemics as a basic fact of life, and that assumption, painful as it is, will protect him when the next threat emerges. But maybe, if the science unleashed by this pandemic lives up to its promise, his children — or perhaps his grandchildren — could inherit a world where plagues are a thing of the past.
Steven Johnson is the author, most recently, of “Extra Life: A Short History of Living Longer.” He also writes the newsletter Adjacent Possible.