Pandemics reshape our social order, wreck economies and replace trust with fear, says Nicholas Christakis, Yale University professor of social and natural science and director of Yale’s Human Nature Lab. But as he points out in his book Apollo’s Arrow, they also elicit kindness, cooperation and ingenuity.
Looking back over both the recent and the distant past, we see that it has always been this way, and that what seems to be new is actually age-old truth that we have simply forgotten. Still, post-pandemic change is not only possible but can be very positive if we take note of lessons to be learned—and then act on them.
The Italian city of Ferrara provides us with a good example. Records show that their disease management strategies during the Italian plague of 1629–31 included modern-sounding nonpharmaceutical interventions (NPIs): hygiene rules and handwashing, self-isolation, improvements to public sanitation, plague hospitals outside the city walls, closure of churches and other mass gatherings, and crucial support for those who were economically disadvantaged. Adherence to these rules helped Ferrara fare much better than other cities threatened by the plague.
Their experience could have helped future populations battle their own disease outbreaks, yet the lessons were largely forgotten until death and desperation forced them back into view.
Daniel Defoe, perhaps best known as the author of Robinson Crusoe, was only five years old when the Great Plague swept through London in 1665. Although three centuries have passed since he compiled his Journal of the Plague Year in 1722, many of his stories and themes will sound familiar to COVID-19 pandemic survivors. We read of asymptomatic carriers, exponential infection and mass graves before NPIs (including halting all but essential trade, closing entertainment venues, enforcing quarantine, and distancing) came into play.
“People used all possible precaution,” Defoe wrote; “when any one bought a joint of meat in the market, they would not take it out of the butcher’s hand, but took it off the hooks themselves. On the other hand, the butcher would not touch the money, but have it put into a pot full of vinegar, which he kept for that purpose. The buyer carried always small money to make up any odd sum, that they might take no change.” Today we transfer funds virtually instead of in vinegar, but the practices of disinfecting and keeping our distance remain.
“When the infection came to such a height as I have now mentioned, there were very few physicians which cared to stir abroad to sick houses, and very many of the most eminent of the faculty were dead, as well as the surgeons also.”
Defoe highlighted a painful reality that persists today: social and economic inequities translate to health hazards for the disadvantaged. Those who could afford to stay safe at home did so, sending others to do their errands in hopes that the plague would pass them by. “All the means that could be used were employed; but then the poor could not do even these things, and they went at all hazards”—at all risk to themselves.
Then, as now, both the best and the worst of human nature surfaced at such times. For some, the fear of death “took away all bowels of love, all concern for one another,” but others rose above, with “many instances of immoveable affection, pity, and duty.”
Other plagues and pandemics came and went, capriciously destroying lives but also encouraging innovation. Cholera, plague and yellow fever outbreaks prompted the establishment of health boards at local levels. Searches for the cause of disease resulted in the growth of lifesaving scientific knowledge. In 1851, nations came together to fight the common enemy of disease with the first of many International Sanitary Conferences, a forerunner of the World Health Organization (WHO).
Progress also came at the municipal level. In the midst of an 1854 cholera epidemic, British physician John Snow correlated local deaths with contaminated water from London’s Broad Street pump; simply removing the handle drastically reduced the spread of disease. Further studies reinforced the need for sanitary sewage disposal and water supplies and helped bring on the Great Sanitary Awakening of the 19th century. As a part of massive public projects, Paris and London installed underground sewage systems that helped prevent human waste seeping into the streets. Naples was eviscerated and replumbed, and the main boulevards rerouted, with a goal of hampering the spread of disease.
In areas that implemented such sanitation programs, the threat of cholera, typhoid and other waterborne diseases diminished greatly, and public health in the Western world improved. An emerging emphasis on handwashing for doctors and on personal hygiene in general also proved essential to reducing the spread of disease in the late 19th century.
But human nature being what it is, as the threat subsided, many of those lessons slipped from public memory.
In 1905, scarlet fever outbreaks prompted bacteriologist Alice Hamilton to investigate the cause. She concluded that streptococcal bacteria caused a particularly lethal form of the disease, and that they spread through “coughing, speaking, whispering, crying or breathing forcibly through the mouth.” Hamilton, the first woman ever appointed to the faculty of Harvard University, recommended the use of face coverings for surgeons and nurses to help prevent infection.
Building on this during the 1911 pneumonic plague in Manchuria (with its 100 percent fatality rate), another bacteriologist, Wu Lien-teh, encouraged the use of cotton masks and implemented strict quarantine rules to isolate the sick. He also advised that sanitary disposal of corpses, restriction of travel, and international cooperation could help contain the disease. Some of Wu’s recommendations were draconian, but he based them on the best knowledge that science could offer at the time, and they proved instrumental in squelching the plague.
“The decisive Wu advised that movement of the population be curtailed; he instructed that plague victims be hospitalised, their homes disinfected and contact prohibited. People were encouraged to wear gauze-and-cotton masks.”
Lessons still fresh from that epidemic were shared internationally and may be, at least in part, why similar safeguards were put into practice when the devastating 1918–20 influenza pandemic swept the world. Through previous adversity, people had perhaps learned that careful hygiene, face coverings and keeping their distance to the best of their abilities (even if that meant closing down society for a while)—and helping those who were unable to help themselves—yielded better results than allowing life to go on as though the allegorical specter of death wasn’t raising its knuckles to the door.
Yet somehow, when that global scourge eventually subsided, the world once again forgot the lessons learned, apparently burying the precious knowledge with the deceased.
Albert Camus lived through the flu outbreak of 1918–20. Like Defoe, he was only five years old when pandemic struck, and his memories undoubtedly shaped his writings as well. In The Plague (La Peste), published shortly after World War II, he captured the fear of an enemy that the five senses could not detect, but also the importance of fraternity and the need to look out for others, to show love and concern for fellow beings. In his novel, we read of the human propensity to forget that which is uncomfortable and then to be surprised when it happens again: “Everybody knows that pestilences have a way of recurring in the world; yet somehow we find it hard to believe in ones that crash down on our heads from a blue sky.”
The collective memories that gave rise to Camus’s words faded as a recovering society plunged headlong into the Roaring Twenties. Over the next century, localized epidemics warned that we should prepare for more; yet when COVID-19 hit, we weren’t ready. Once again we retained little memory of lessons from the past and had little idea of what lay ahead.
Of course, hindsight is 20/20. And in early 2020, most people didn’t believe—or didn’t want to believe—that the world was cresting a rollercoaster ride into waves of global pandemic. Officials were reluctant to enforce restrictions in an age when the desire for personal freedom often trumps sacrifice for the greater good. And because early recommendations were inconsistent, confusion and inaction ruled the day.
Christakis bemoans those mixed messages. He notes, too, that “the lack of testing was a huge blunder, and it drastically slowed the response to the early infections.” Death rates soared, confirming that COVID-19 is substantially more fatal than seasonal flu, with a mortality rate at least 10 times higher than for most influenza strains. Yet downplaying the importance of NPIs became a point of political pride in some countries, with partisans seeming to value perceived economic benefit over human health. “Americans,” Christakis chides, “had put on blindfolds when they should have put on masks.”
“Epidemics end. But how we get to that point defines us and our own moment facing down this ancient threat.”
An Imperial College London report for the WHO concludes that we might have reduced the need for healthcare intervention by two-thirds and reduced deaths by half had we much earlier implemented mitigation policies using NPIs such as home isolation, quarantine and social distancing.
Christakis cites a policy analysis from his colleagues at Yale: If at least 70 percent of the population had started wearing reasonable masks right away, we could have prevented a large-scale outbreak of COVID-19. No single intervention is perfect, of course, so the early, widespread addition of careful handwashing and distancing would have greatly increased the odds of success. Christakis promotes this “Swiss cheese model” (imagine layers of Swiss cheese, each slice covering the holes in other slices), adding that multiple layers of contact- and transmission-reduction measures would have brought the pandemic to heel. The US Centers for Disease Control and Prevention (CDC) and scientists at Imperial College London similarly encouraged layering NPI interventions to stop or at least slow the spread of COVID-19.
Medical historian Peter Hobbins, in an article published by the Australian Broadcasting Corporation, reflected on the history of such layers: “Despite all the advances in our health care system . . . in the last hundred years, ultimately we’ve still had to fall back on the sorts of measures that we saw were effective in 1918 and 19, including good nursing care for victims, quarantine, social isolation and basic measures like masks and sanitation. Sometimes what we know from the past still turns out to be the most effective response that we have.”
One of the earliest written records still available today outlines measures that seem to form a type of health guide, which some consider the foundation for hygiene rules, public health and, later, the science of pathology. Today we would call many of these measures NPIs.
This guidance, found in the Hebrew Scriptures, was given to refugees gaining their freedom from slavery in Egypt. The Israelites were beginning anew, and as they traveled across the desert, they were given instructions on how to balance their newfound freedom with essential responsibility for health and mutual welfare, working together for the greater good.
Like so much basic knowledge about health and hygiene since then, these instructions were largely abandoned over time, being seen as little more than religious or ceremonial ritual. It took thousands of years and untold pandemics for humankind to discover (and rediscover) the wisdom underlying many of these ancient practices.
History shows that nonpharmaceutical interventions such as quarantine, distancing, sanitation and hygiene can help slow or stop the spread of most diseases—eternal truths that are reaffirmed with every pandemic. Yet the end of each episode ushers in what Camus called “the living warmth that gives forgetfulness of all,” and we fall back on old routines.
Then along comes another pandemic, bringing us all to our knees, deflating our hubris. Pandemics arrive, fade away and return in a different form, periodic reminders that we are not omnipotent after all.
“Those who cannot remember the past are condemned to repeat it.”
By increasing immunity in vulnerable populations, we’re able to manage disease outbreaks, but for the most part those diseases don’t actually go away. Nearly every infectious disease known throughout human history is still with us today (smallpox being a notable exception), and novel viral pathogens continue to emerge and assault populations that have never been exposed to them. In the context of the coronavirus that causes COVID-19, Christakis observes that “humans will have to reach a modus vivendi with this virus. . . . A new pathogen has been introduced into our species, and in some form, it will now circulate among us forever.”
Yet there is hope as people work together, sharing knowledge and sacrificing for the benefit of all. The protagonist in The Plague, a medical doctor who serves as the novel’s narrator, resolved that he should “not be one of those who hold their peace but should bear witness in favor of those plague-stricken people; so that some memorial of the injustice and outrage done them might endure; and to state quite simply what we learn in time of pestilence: that there are more things to admire in men than to despise.”
Throughout the history of plagues and pandemics, we see progress whenever public health became a societal goal and protecting health became a publicly shared responsibility. Despite what some may feel are their personal rights, plagues demand that we work together or die; we must find the humane balance between the needs of the many and the wants of a few. But the recent pandemic shows how easy it is to forget our responsibilities toward one another. For some, simply wearing a mask to protect oneself and those around seemed to be an affront to personal rights and freedoms.
For the Common Good
The COVID-19 pandemic also showed—again—that those who are disadvantaged socially or economically and have limited access to resources suffer the most from pandemics.
Pharmaceutical corporations seized the moment in 2020, developing and dispensing vaccines with unprecedented speed, thanks in part to the knowledge and experience they had acquired from working with similar viruses. But as with access to personal protective equipment, medical equipment and other resources, the vaccines were disproportionately available to developed countries with ample funding and facilities. Within those countries, access was further skewed in favor of those with such resources as transportation, internet access, smartphones and savoir faire.
These disparities provided an opportunity for extremists and charlatans to exploit the disadvantaged, promoting conspiracy theories and misinformation, or providing false hope with a proliferation of substandard or fake vaccines and questionable cures. In some cases criminals even stole or redirected vaccines and medicine for personal gain.
The other side of that coin found people rising to the occasion, advocating for marginalized groups and individuals, banding together, helping small businesses stay afloat, supplying food and other essentials to those in need, supporting vulnerable communities, and providing assistance when finances, language or other barriers prevented people from getting the help they needed.
While COVID-19 vaccines provide protective benefits, not enough time has passed to determine just how long that protection will last. In any case, no vaccine guarantees 100 percent protection. The point is that responsibility—for our own health and for the health of others—does not end at the tip of a needle. As with all communicable disease, until the chance of disease transmission passes, wisdom dictates that we continue to follow the age-old, tried-and-true principles of hygiene, sanitation, distancing and quarantine that have cycled in and out of our awareness since ancient times.
When a pandemic crisis abates, people tend to forget the lessons and dance on as though pestilence, plague and pandemics weren’t shackled to the human experience, ready to bring us down again at a moment’s notice.
Camus’s words ring true today: “Our townsfolk were not more to blame than others; they forgot to be modest, that was all, and thought that everything still was possible for them; which presupposed that pestilences were impossible. They went on doing business, arranged for journeys, and formed views. How should they have given a thought to anything like plague, which rules out any future, cancels journeys, silences the exchange of views. They fancied themselves free, and no one will ever be free so long as there are pestilences.”
We all long for a new era of true freedom and universal cooperation. But until that materializes, every time we encounter a health crisis, whether individual or collective, we do well to learn from the past as we prepare for the future, working together, sharing knowledge and truly caring for others without an agenda of personal, political or financial gain. We do well to prepare for the next time—for there will certainly be a next time.
“There have been as many plagues as wars in history,” warned Camus, “yet always plagues and wars take people equally by surprise.”