We have been quarantining since before the invention of germ theory. Why do we quarantine and what can we learn from pandemics of the past?
Cover Image
Original art ©Patrick Kelly, 2020
Full Text: It’s June, I’ve been stuck inside for months, all the restaurants are opening up and I’m literally dying of boredom. Can I hang out with my friends yet? The answer is no. I’m Peter McGuire and this is my Unlikely Explanation.
“The stranger rode beside her, easily, lightly, his reins loose in his half-closed hand, straight and elegant in dark shabby garments that flapped upon his bones; his pale face smiled in an evil trance, he did not glance at her. Ah, I have seen this fellow before, I know this man if I could place him. He is no stranger to me.”
This is the premonition that the protagonist of Katherine Anne Porter’s Pale Horse, Pale Rider wakes with on the morning of her influenza infection in 1918. The short novel depicts a young newspaperwoman in Denver, Colorado who emerges from her illness shaken to the core and profoundly changed. She emerges into a very different world than she left.
“No more war, no more plague, only the dazed silence that follows the ceasing of the heavy guns; noiseless houses with the shades drawn, empty streets, the dead cold light of tomorrow.”
Porter herself worked for the Rocky Mountain News here in Denver and fell gravely ill during the 1918 pandemic. She wrote Pale Horse, Pale Rider in 1939, just as the world was descending into yet another war. Two decades after the devastation, she was still processing the experience. She was not alone in carrying the psychological and physiological scars for the rest of her life.
Over the last few months, many of us have seen a pretty significant change in our lives. We are living (and dying) in historic times. The only other event of this magnitude in my lifetime was 9/11. Approximately 3,000 people died in the attacks on September 11th, 2001. As of May 15th, an average of 2,000 Americans have died every day for the last 30 days. The two events are incomparable—they are completely different in nature—but the numbers help us get a sense of the scale of how much we are affected by this pandemic. Since early April, every two days, Americans lose more countrymen than we did on 9/11. The daily death rate continues to grow and it is impossible to say how many people are currently infected or will be before this is over. We appear to have just peaked but it’s hard to know whether there will be a second phase of infection or what that might be like. What is clear is that this will leave a lasting impact on our society and our psyche. This will change the way we see the world. We are witnessing nothing close to the severity of the plague that Katherine Anne Porter did in 1918, but we also don’t see deaths that were commonplace in Porter’s day from a huge range of illnesses that have been cured or mitigated. Death from illness like this is not normal in 2020 and that is why it’s so shocking.
Today, I want to look into some of the cultural objects that will stick with us: the quarantines, the masks, the economic closures, and (something we will hopefully see before long) the vaccine. Why did Covid hit us so hard and why did we respond the way we did? The answer lies in our history: the successes and failures we carry as a society. Let’s try to understand these pandemic times better by looking at the history of medical science, our system of public health, and the event so traumatic that it shaped modern medicine: the influenza pandemic of 1918.
Humans have been using quarantine to combat disease since ancient times, long before the development of germ theory. It features in many ancient religions as part of the idea of ritual purity. Persons who violated social taboos were set apart from the community as unclean and often physical illness was treated as a form of degeneracy that was spread through contact. An example of this comes from Leviticus, written around the 7th century BCE, where a seven to fourteen-day isolation is required for people exhibiting ringworm-like symptoms. I have read that the proscriptions against shellfish and pork in Leviticus were public health guidelines since those animals must be cooked properly to be safe to eat. In ancient times, things we consider different parts of public life such as government administration, religion, and law were tightly entwined. That is why Leviticus, essentially a legal and moral code for an ancient Jewish society, is still considered a holy book by virtually all Christians, Muslims, and Jews. It presents health advice, laws, and moral codes under the same framing of clean vs. unclean. It places our ringworm patient in the company of lepers, menstruating women, crossdressers, and homosexuals. This association between illness, taboo, and social deviance wasn’t excised from medical practice until the 20th century and still lives on amongst faith healers and televangelists in America today.
We get the term “quarantine” from the Venitian term for forty days. This was the period of time that ships had to wait to dock in Venice at the height of the Black Death. In the 14th century, several cities found that stopping the flow of people could slow the spread of plague. The city of Ragusa on the Dalmatian coast had success requiring visitors to stay isolated on a nearby island or on their ship for thirty days before entering the city. The Venetians, further up the Adriatic Sea, on the Italian side, instituted the same policy but with a length of forty days. This apparently worked as well as it did because the progress of the bubonic plague took thirty-seven days from infection to death. Quarantines were established because they worked.
Prevailing medical theory ascribed the plague to bad air, called miasma, usually triggered by the machinations of the stars. Astrology formed the basis of many medieval theories about fortune both on a personal level and for civilization as a whole and health was considered a component of personal and societal fortune. It is no coincidence that the first cities to adopt quarantine were the port cities of the Mediterranean. It passed from Asia along the newly open Mongol trading routes into the ports of the Turkish and Byzantine Empires and then passed from the ports on the south coast of Europe into the mainland through traders and travelers. It is no coincidence that the first quarantine islands used by these port cities were converted leper colonies. The isolation of plague victims was inspired by the ritual purity idea that kept lepers isolated.
We now know that quarantines work because communicable disease—disease that can be transferred—is primarily caused by microscopic organisms. Quarantine is especially effective against diseases like leprosy and bubonic plague because they are not very contagious. Yes, I am saying that the plague that killed a third to half of all Europeans wasn’t very contagious. I will come back to that. First, let’s consider leprosy. 95% of people exposed to the leprosy bacteria do not contract the disease. It requires prolonged, close contact with an infected person to have a chance of becoming infected and, even then, some people are genetically immune. Therefore, it’s the perfect disease for a society to learn the idea of quarantine from. Even minimal quarantining can reduce the spread. It makes sense that there should be religious taboo around lepers because there’s a reciprocal relationship between reality and human culture. In a time when religion and philosophy are one in the same, the fact that isolation of disease saves lives enters law as a religious proscription. The idea of isolation becomes amplified in the culture by reciprocation between its effectiveness as a health policy and its use in marginalizing social deviants. The ill and the odd become stigmatized classes.
The ritual purity idea continues to this day in our treatment of social deviance. Cultures around the world since ancient times have put social deviants classed as criminals in prison for reasons ranging from isolation to punishment to reform. The United States of today has embraced this idea wholeheartedly and currently imprisons more people than any country ever in history, three times as many as we imprisoned in 1980. We also take this a step further with the idea that felons legally must disclose their criminal past to prospective employers, which keeps them from ever fully reintegrating into society. This is a form of ritual cleanliness that increases recidivism by keeping felons on the margins of society. But it may also be true that felons have a natural recidivism rate, that a felon will commit another felony for similar reasons as the first one. It may be that there is a reciprocating effect between reducing the social impact of crime and stigmatizing felons as undesirable members of society.
This is taken to yet a further extreme with sex offender registries. Sex offenders must disclose their status to neighbors, join the state registry (which prevents employment in many cases), and stay a certain distance from places like schools, playgrounds, and churches where children congregate. This can make the majority of space in cities off-limits to sex offenders and lead to the creation of sex offender colonies where sex offenders, mostly homeless, become a hotbed for crime, drugs, prostitution and, of course, disease. It’s possible that this makes cities safer. It’s certain that this keeps convicted criminals ritually isolated.
Jails are hotbeds for disease. Disease spreads most effectively in cramped, unsanitary conditions. Today, the coronavirus is ravaging prison populations due to crowding in relatively sanitary conditions. Historically, jails were extremely unsanitary. Often small, dark, and crowded, jails had no plumbing or regular cleaning. Jails served as repositories for disease and a vector for continually reintroducing it into the rest of the population. Typhus came to be called gaol fever and typhus epidemics were commonly understood to follow wars and famines, anytime people were forced in close, unsanitary conditions. We can also see the process of disease transmission very clearly by looking at medieval English courts.
During and after the Norman invasion, compromise formed between rural Anglo-Saxon aristocracy and the new Norman king. The king had sole authority to decide most legal suits, and in return, the king could take his court on regular circuits throughout the country dispensing justice. Eventually, this turned into a system of devolved powers, but in the medieval and early modern periods, direct representatives of the king would travel along the circuit, dispensing rulings castle by castle. This provides a perfect example of disease reservoirs and disease vectors. Accused criminals would be kept in the local jail until the next visit by the circuit judge. All judges and most plaintiffs were of the noble class while most accused were not. After stewing in the jail diseases for a few months, prisoners were brought to court where they shared space with nobles and cityfolk. Sometimes disease would spread into the general population. Sometimes the nobles would catch it. Frequently, the judges would then pollinate these diseases from town to town along their route. We hear from 1577 of the Black Assize of Oxford in which over 300 people died of “jail fever” during and after one of these court sessions. You would be right to wonder why it is notable for 300 people to die of typhus in medieval England. The answer is that the Black Assizes of the 16th century killed magistrates, members of the aristocracy.
Disease is classist. Microorganisms attack people indiscriminately but don’t always have the opportunity. Slums make great disease reservoirs for the same reason that jails do: they are crowded and unsanitary. Disease has more opportunities to attack and their targets are less effective at fighting it off. We can see this even in the Black Death. Samuel Pepys, an aristocrat diarist and civil servant, saw plenty of death as the plague flared up in London in 1665, but it affected him little personally. While his servants died, Pepys worked, socialized, and partied like never before. The immune system is affected by things like nutrition, exercise, mental health, and air quality, things the working class can’t afford. For this reason, most cities through most of history experienced more deaths than births each year. The majority of city growth has always been the result of immigration. This changed suddenly in the 20th century due to the advances in medicine and nutrition and world population exploded from around 1 billion in 1800 to 7 billion in 2011. It took about 200,000 years of human history for the world's population to reach one billion and only 200 years more to reach 7 billion.
When disease moves through a population, it is always the people on the margins who are hardest hit. I mean the people who are poor, elderly, homeless, unemployed, or discriminated against. These are the groups that benefit most from improvements to public health.
One of the first major public health interventions came in 1854. As in the 14th Century, the leading explanation for plague was still miasma. “Bad air.” The miasma theory of disease had now moved from astrology as its ultimate cause to the unsanitary conditions of the poor. For the people of the 19th century, this still had a moral implication. The poor were assumed to live in squalor because of a lack of personal responsibility for their homes and neighborhoods. Victorians railed against the sin of idleness, the idea that the squalid conditions of the poor were caused by a lack of initiative on their part. The services needed to improve cleanliness were not available.. No proper sewers had been dug, the only garbage collection was done by dustmen who only collected things that could bring a profit (however small), and residents worked 10 to 16 hour days in factories. It is particularly cruel to tell people who are working 16 hour days six days a week that they live in poverty because of their laziness.
John Snow was a 19th Century physician who had qualms with the miasma theory of disease and believed that it was caused by a contagious poison that had to be ingested into the body through contact with some contamination. Critics mocked his “morbid matter” theory. Snow interviewed households in Soho and noticed that almost all of the cases were in a certain neighborhood that got water from the same source: a shallow well. He later demonstrated the effect of the well with a dot map, one of the first infographics. A key detail that confirmed Snow’s suspicion was that workers at the local brewery weren’t getting cholera, presumably because they were drinking their beer ration instead of the local water, and the water in the beer had been boiled as part of the brewing process. Authorities agreed to remove the handle of the well and before long the epidemic passed. Snow claimed that this vindicated the idea that a pathogen had been passed from feces to the drinking water. The well had been infected by poorly maintained cesspits in the area. Despite the success of Snow’s recommendations, the health board investigated and determined that miasma had been the cause. Some doctors were so against the concept of a disease molecule that they went so far as to drink cultures of the cholera bacteria. They experienced a range of cholera symptoms, usually mild. Presumably, this is because they had relatively little exposure and lived in conditions where their bodies could fight off the disease easier than urban workers could.
Once a disease exhausts its possible hosts, it itself dies. A pathogen needs a sustainable life cycle. This should make you ask, then why should a pathogen kill at all? Wouldn’t it be more sustainable if it was symptomless? The answer is that most killer microorganisms kill by accident.
The black death, a bacteria, doesn’t want to kill, it wants to spread. All pathogens are this way. In birds, influenza basically causes diarrhea as its method of spreading and it is much less deadly than human influenza. In fleas, the plague bacteria causes vomiting. Bacteria multiply in a specific part of the flea’s gut which blocks it and causes the flea to starve. In an attempt to feed, the flea bites more and more victims but, unable to properly swallow the new blood, the flea regurgitates blood into the bite wound blood along with thousands of bacteria.
This process mostly takes place between fleas and rodents. Some rodents die of the infection, but most live, and it passes between the two. There are cases when the flea population outruns the rodent population and the fleas go in search of other kinds of blood to fill their guts. This is the main way that the bacteria finds its way into humans, where it wreaks all kinds of new havoc, and ultimately killed between a third and a half of all Europeans.
The plague is like the flea, it is a kind of parasite. Parasites don’t evolve to kill their hosts, or at least not many hosts. If a flea can only feed on rodents and the rodents die, the flea dies. That’s why the flea only sucks a small portion of the rodent’s blood and then moves on. The flea spreads the plague because the bacteria has hijacked its impulses. It cannot satiate its hunger and so it continues to bite and spread bacteria. Similarly, the bacteria doesn’t want to kill the flea or the rodent, at least not in significant numbers. But if all the rodents were to die, the flea has a backup plan. It can also drink the blood of other mammals. The bacteria shares this strategy. If it cannot infect rodents, it will try to infect other animals. In many cases, it will be unsuccessful. It is evolved to interact with rodents in a certain way and those strategies may not work on other animals. But when it finds its way inside of humans, its tools for infecting are devastating.
It's easy to get the idea that single-celled organisms are less cunning in their survival strategies than animals of our size. Nothing could be further from the truth. No matter how simple or complex a life form is, how ancient or newly evolved, we all fight for the same resources. It’s easy to get a bit chauvinistic about the complexity of other life forms. After all, we have thumbs and build cities. But you yourself are a city built by single cells. Your body is a tremendous cooperative effort pulled off by trillions of cells with specialized jobs, most interacting with the others only indirectly. In cooperation with the cells that contain your DNA, there is an equally complex network of single-celled organisms working to turn the multicellular organisms that you eat into chemical energy. To them, you are not a more complex form of life, you are an environment, a new ecological niche where food is delivered right to their homes. Some of these organisms evolved before the first fern poked its fronds above the water. Some of them, like the Coronavirus, evolved last year. There are multicellular organisms that reproduce by spraying sex cells randomly into the ocean. There are parasitic fungi that cause their ant host to climb a blade of grass and announce its presence to predator birds which incubate the next phase of the fungus life cycle. Antiquity and complexity have no bearing on natural selection. To the pathogen, you are what the field is to the farmer. Whether you are exhausted of your usefulness and die or survive and continue to support the pathogen (or evict it entirely) depends largely on how aggressively the pathogen exploits its environment: you. There are over a hundred types of Human Papillomavirus that circulate endlessly in the human population and only the human population. The nine types that cause cancer are the nine types that we vaccinate against. A successful parasite is one that does not upset its host.
Of the fifteen hundred or so pathogens that affect humans, 61% evolved to attack a different animal. Here are a few diseases and the animal that they evolved to attack. African sleeping sickness, anthrax, trichinosis and salmonella attack livestock; Giardiasis, a disease caused by a parasite that I have had the absolute pleasure of hosting personally, attacks forest wildlife like deer and is endemic in rivers in America. Leprosy attacks armadillos and rodents. Influenza predominantly circulates in birds and swine; Ebola, the HIV predecessor SIV and Zika virus attacks monkeys; and everyone’s new favorite disease, SARS-CoV-2, predominantly attacks bats. Most of these diseases cause mild sickness in their intended host that helps them spread like vomiting or diarrhea. When they leap to humans, they become much more deadly.
The late 18th and 19th centuries represent a perfect storm for disease. As technology changed economies in Europe and then the rest of the world, economic centers shifted from rural resource gathering to urban resource processing. Advancements in agriculture allowed for a growing population boom that forced people from the countryside into cities to find work. This brought a huge influx of people into large cities where, as mentioned before, many lived in cramped, unsanitary conditions. They also brought with them their own local strains of animal-borne diseases. This created a perfect petri dish: pathogens converging from all over countries into cities, which were then shared between cities by travelers who could now move farther, faster than ever. Diseases could never “run their course”. This was a fire that could not run out of fuel because fuel—in the form of urban workers—kept arriving daily.
In the 19th century, the majority of deaths were attributed to diarrhea, fevers, and lung infections. Today the top causes of death are heart disease, stroke, cancer, and non-communicable disease. Communicable disease has all but dropped off the map in terms of causes of death. Since the 1950s the global death rate has dropped from 2% to .7% of the population per year, in large part due to public health campaigns. How do we explain such a huge shift? We see medicine and the practice of public health come of age in the 20th century, propelled by science, war and pandemic.
Most medicine up to this point built on the work of the Roman physician Galen, who devised a system that explained how the four elements—earth, air, fire and water—affected the body in the form of four fluids: blood, phlegm, yellow bile and black bile. Each of these humors had a connection to astrology and personality, and the balance within the body was supposed to control health as well as fortune. Recall that the medieval system saw health as one aspect of a person’s life experience which was dictated by forces like God and the movements of the stars. One’s material realities represented only one aspect of this complex system of retrograde and prograde and hot and cold and choleric and phlegmatic. This worldview is deeply embedded in our language. The term for the disease cholera comes from the greek (“khole”) for bile since it was meant to be caused by an excess of it. If I am habitually afflicted with black bile, then I am “melancholy”, from the Greek “meles” meaning black and “khole” meaning bile. It’s the Ravenclaw of humors. If I get too upset I might vent my spleen, the organ that makes the black bile, which means I will argue and complain. The terms lugubrious, morose and wistful all refer to this condition. This humor is associated with the celestial body and god called Saturn, so when Saturn appears to move backward in the sky, a phenomenon caused by the rotation of the earth and the orbit of Saturn, then Saturn is said to be in retrograde and I may experience ill effects from my governing humor. Ideally, if I am too full of black bile—acting morose and mopey—then I should take laxatives to purge it. The most common version of this was the treatment for too much blood, which governed rage and was controlled by the celestial body Mars, the god of war. Exsanguination—bloodletting—became the most popular method for balancing the humors so much so that the top medical journal in the world today is named for the tool for bloodletting: The Lancet.
Slowly, evidence began to mount that tinkering with body fluids was not in fact balancing the body. As the 19th century progressed and more and more specific cures were found for specific diseases, a new theory began to take shape. Rather than grand explanations about the universe, as more data came to be collected and associated with illness, it became clear that most disease spread under specific conditions. As the scientific method developed, some of these effective early methods came to be tested in laboratory conditions.
At the same time, new ideas were developing about the nature of life. Scientists found it useful to look at all manner of samples with greater and greater magnification and before long it was discovered that living things are made up of cells. The cells could have massive variation in shape and size, but nevertheless the world was teeming with organisms that could only be seen through a microscope. Soon after, it was found that most organs of the body were made up of similar-looking cells. These networks of similar cells were called tissues. Connections were then made between certain pathogens and the tissues that they affected. Looking at diseased tissue under a microscope opened up a new world of treatment because scientists could see the organisms associated with the illness multiply or die in real-time when exposed to various chemicals. A new orthodoxy began to develop slowly which suggested that treatments could be made of potentially hazardous materials that could be targeted at specific organisms that caused specific diseases. Suddenly another piece of medical orthodoxy made sense.
As early as the 16th Century, Chinese doctors were conditioning the human immune system. Scabs formed from certain infectious diseases were ground into a powder and then dropped into scratches on the patient’s body. Sometimes this conferred an immunity or resistance to the disease that caused the scabs and other times the patient would become ill or even virulent.
In the 1760s, in England, Edward Jenner was inspired to test a piece of folk wisdom. A forgotten aspect of the Enlightenment movement was that it often looked to folk remedies as starting points for empirical testing. He had heard that milkmaids never got smallpox but they frequently had cowpox infections. Both of these conditions, as well as chickenpox, are named for the inflamed, painful pus-filled pimples they cause which are called pox. Cowpox and smallpox are caused by closely related viruses. Cowpox predominantly affects cows and was mainly seen in humans only the hands of milkmaids who milked infected cows. Today the disease lives on mainly in the U.K. and is transferred by cats. Jenner found that scraping a patient with a needle contaminated with the pus from a cowpox pustule made them immune to smallpox so much so that he could (and did) inject them with smallpox scabs to test it. This was the only vaccine for about a century and the term that we use, “vaccine”, is derived from the latin for cow because of the connection with cowpox. This smallpox vaccine was so refined that it became the test subject for the first global program to eradicate a disease. In 1979, the World Health Organization certified that the smallpox virus no longer exists in the human population. The first vaccine caused the first eradication of a disease.
In the late 19th century, we get a series of discoveries in quick succession: Ignaz Semmelweis, a Hungarian physician with a very tragic story, discovers that washing hands after performing autopsies can slash death rates caused by infections contracted in the hospital. In France, Louis Pasteur discovers that fermentation is not a chemical reaction, it is carried out by microorganisms and that life will not spontaneously generate in a closed system. He pioneers the system of “pasteurization” which essentially kills microorganisms by heating a liquid like milk or juice above the bateria’s die-off temperature for a certain period of time. In Germany, Rudolf Virchow declares that all cells come from cells, which sets the stage for modern biology and evolutionary theory. Also in Germany, Robert Koch creates a system for connecting diseases to a specific pathogen which more-or-less completes germ theory. The English doctor Joseph Lister demonstrated the practical application of sanitization in surgery and slashed the incidence of postoperative infections. An American company years later would use his name for their brand of Antiseptic mouthwash: Listerine. Suddenly hundreds of diseases were tied to their causes and new vaccines, serums and techniques rapidly transformed the way we understand health.
By 1918, American medicine was quickly catching up to European medicine thanks to grants from the entrepreneurs Johns Hopkins of Baltimore and John D. Rockefeller of New York. The Johns Hopkins Hospital had earned a reputation as a model clinic for its evidence-based approach to treatment and clinical trials that carefully adhered to the scientific method. It had become an incubator for the greatest doctors of the generation. Rockefeller Institute for Medical Research, helmed by Abraham Flexner, was the leading research institution doing model laboratory research into vaccines and cures. This Institute had recently been incorporated into the United States Army as “Army Auxiliary Laboratory Number One” and remained the only army laboratory. The war had changed many things in America, most notably the economy. Across the board patriotic fervor was stirred up while huge contracts came out of Washington. Wilson used every arm of the federal government to transform America into a fighting machine and he’d been successful. Now boys were leaving small towns across the country to join up at cantonments and eventually ship out to the western front.
This should sound very reminiscent of the situation over the previous century caused by industrialization. Men, many of them farmers and ranch hands, were congregating at camps with insufficient space, food, and heating. The men huddled around stoves in thin blankets waiting to be packed onto trains to continue their progress towards Europe. Army doctors were already on high alert for an epidemic. Doctors had noted epidemics after conflicts over the past few centuries and now the mechanism was clear. Armies coming in contact with armies from other countries picked up new pathogens and brought them home to civilians when they demobilized. The only question was which disease it would be and how much progress had been made against that disease. In fact, an epidemic had already struck the army: measles. So much working time was being lost to measles outbreaks that army commanders had instituted some (not many, but some) of the regulations that doctors demanded: quarantining infected camps, better supply, and more sleeping space. Keep in mind, this doesn’t even include the soldiers who were already in Europe, these are problems at home.
That is why, when the first few reports of influenza appeared, administrators took little notice. Influenza was nearly as common as the cold and although it could be deadly, it wasn’t as severe as things like measles or pneumonia and far more contagious. Starting perhaps as early as January, a weak flu strain began to circulate and in the middle of summer, a wave of flu swept across the globe. Opinions differ on the starting point, but very likely the mass movement of troops caused the disease to circle the globe very quickly. Some health professionals rejected that the disease could be flu because it wasn’t deadly enough. While most major countries were at war, most bad news was suppressed either by the government or the newspapers themselves. Anything that could potentially hurt morale was seen as unpatriotic and newspapers did not want to be unpatriotic. This is a time when men who couldn’t be drafted for whatever reason volunteered to bully people in their workplaces into spending their last dime on war bonds. The crime of criticizing the war could and did land people in prison. One of the few uninvolved western countries was Spain and the Spanish press reported on the flu freely throughout the war including when the king Alphonse XIII came down with flu. This earned it the name “Spanish flu”.
By August, the flu pandemic had died down. Even more incredibly, the allies began to make progress on the western front. Across August and September, most assessments came to realize that victory for the allies simply a matter of time. It appeared that the worst of the killing had come and gone and the world was still standing. Word spread that the flu was disrupting the German war effort. Then the flu returned, deadlier than ever.
If we want to compare the coronavirus pandemic of this year to the influenza of 1918, we should start with the differences. Coronavirus and influenza are only distantly related. Their similarity comes from them both being RNA viruses, how they spread, and how they kill. All living things mutate from generation to generation, meaning that the genes of the children are not identical to the genes of the parents. DNA has a proofreading system built into its duplication. RNA does not. That means that RNA viruses can change quite drastically from generation to generation which makes them harder to vaccinate against and target. It also means that their method of attack is quite similar. They lock with a receptor on one of your cells, essentially telling that cell that it can come in because it is part of the body, and then it hijacks the cell’s reproduction system to produce copies of the virus’ RNA. The cell eventually bursts and all the new baby viruses spill out into the system to infect other cells. A side effect of this is that two different RNA viruses can infect the same cell and since they’re just spraying their RNA into the cell, these different viruses can join up and recombine in new ways. This is part of how a virus can leap across species. If a human influenza and a swine influenza were to infect the same cell at the same time, the offspring can potentially infect either or both hosts.
It is important to remember that the 1918 influenza was significantly more widespread and deadly than our coronavirus pandemic. Influenza infected somewhere around a third of all people and it killed somewhere in the ballpark of 25 million people. Even if we see another major peak to this pandemic, it is unlikely the death toll will approach 1 million and the proportional number is even smaller because 5 billion humans have been born since then. 5 billion!
The method by which the two viruses kill is similar. Coronavirus causes SARS—Severe acute respiratory syndrome—which exhibits as a fever along with typical cold symptoms and ultimately kills by compromising the lungs. Once lungs begin to fill with debris from the fight against the virus, secondary infections set in. Influenza kills in a similar way, through a condition called ARDS—Acute respiratory distress syndrome. The strain in 1918 was so effective at turning the immune system against the lungs that doctors in autopsy would find lung tissue light and spongy to the touch. Physicians had only seen anything like it in poison gas attacks during the ongoing war. When the lungs can’t clear themselves from coughing, pockets of infection can set into the lung tissue which is called pneumonia. Doctors in 1918 had serum to fight the pneumonia bacteria but antibiotics hadn’t been invented yet. Despite the huge flurry of research caused by the incredibly deadly pandemic, the cause wasn’t discovered to be a virus until 1931 after it was identified in pig populations. The cause was assumed to be one of the many bacteria that opportunistically attack the lungs and so the methods attempted for conveying immunity against the influenza failed. The best doctors could do was fight the pneumonia bacteria. In our fight against coronavirus, we already know our enemy.
Another advantage we have has to do with the virus’ genes. Influenza viruses don’t tend to be one species. We name them based off of the receptors they have which determine how they dock with other cells. For example, the 1918 flu and the 2009 outbreak were caused by H1N1. The “most likely to cause a pandemic” had been H1N3 up till 2009 because that was the flu that circulated in pigs for most of the 20th century. Instead, a new influenza virus appeared of the H1N1 form that had genes from human, avian, and swine flu lineages. Despite having the same shape, groups of flu viruses don’t have one specific genome that centers the group. Instead, they are called a “mutant swarm,” a group of organisms that act together and are similar but not similar enough to act as a single species. Coronavirus, on the other hand, has very little genetic variation. This implies that it was discovered quickly. It probably only evolved sometime in the fall or winter of 2019, meaning that the first cases caught in January of 2020 were likely some of the first cases. This should make the coronavirus easier to target with a vaccine.
The symptoms we see from coronavirus are frankly less scary than the symptoms of 1918 flu. Keep in mind that neither the strain, nor the receptors, nor the genes can easily account for differences in severity. It was presumably the same disease that attacked in the summer and the fall but the second wave was much more deadly. Pockets of death and survival around the world can only be partly attributed to environmental causes. The 2009 novel H1N1 caused nothing like the symptoms of the 1918 strain.
The first thing that scared people was the blood. Ships carrying infected soldiers across the Atlantic would arrive in France with blood literally sloshing around the decks. The 1918 flu had a particularly strong tendency to attack mucous membranes and degrade the tissues, so mucous membranes of the nose, throat, mouth and even the vagina and anus could easily rupture and bleed. People experienced soaring temperatures accompanied by intense headaches, vomiting, and aching of the joints. Some spent weeks in agony from what was called “breakbone fever” because of the pain in the limbs. Lung damage in many patients caused cyanosis, which is when extremities go blue from lack of oxygen. As the pandemic progressed, doctors and nurses considered patients with cyanosis to be walking dead and would even put toe tags on living patients who had gone blue. Some went into coma-like states as they battled through fever after fever. Katherine Anne Porter had such symptoms, which she describes like this, “She sank easily through deeps and deeps of darkness until she lay like a stone at the farthest bottom of life, knowing herself to be blind, deaf, speechless, no longer aware of the members of her own body, entirely withdrawn from all human concerns….” Some felt this brain fog for the next few years, some for the rest of their lives.
Another terrifying aspect that we don’t need to contend with was the loss of particularly young and strong members of society. When you graph mortality of a disease against age, you typically get a U shape. Disease typically kills people with weaker immune systems so the very young and very old tend to be hardest hit. The 1918 flu had a strange W shape to its curve. A peak in deaths existed for the very young and very old but another peak centered around the age 25. This has to do with the way the virus caused death; the damage done to the lungs was typically done by the patient’s own immune system, meaning that those with the strongest immune systems were also hard hit. For the 1918 pandemic it was best to be an adolescent or middle-age. This made the virus have greater cultural impact, as the most visible members of society were hard hit.
Contrast this with the stats coming in from this pandemic, which show a pretty exponential graph by age. It looks like the right half of a U shape. Strangely, infants and toddlers show the lowest death rate while the elderly have by far the highest. This has impacted our response to the virus. Since the hardest affected, the very elderly, are already outside of the labor pool, have little agency over their lives and little political power, their voices have been silenced. This group is also most likely to follow radical right-wing news sources that have propagated conspiracy theories about the virus and discouraged taking action. So, the group that is hardest hit has little ability to demand action and less incitement to.
The main value in comparing our pandemic to theirs is because the two diseases spread in much the same way. We’ve discussed how they are both RNA viruses, they share symptoms, and they kill in a similar way. The symptoms are also their method of spreading. Influenza and coronavirus mainly cause diarrhea in their main host species: birds and bats respectively. Poop dropping from flying animals is a pretty effective way to spread disease. In humans, the mucus buildup, coughing, sweating, vomiting and diarrhea are all ways that these pathogens can spread. The main way that they spread is through contact. That’s why the most effective defense is washing hands and not touching your face, where the virus can enter your system.
A secondary method these viruses use to spread is through the air via small droplets of liquid. This usually means snot or spit from sneezing, coughing, talking, or just breathing. I’ve been seeing some controversy, if you can call it that, around masks. Some cities, including my beloved Denver, require you to wear a mask to go inside of retail stores. The masks that most people are wearing are made of cotton. The masks widely used in 1918 were gauze. The weave of these materials is way too wide to prevent tiny droplets from getting to you. The main value of the masks is to prevent larger droplets produced from coughing or sneezing from going anywhere. This has to do with how much virus is being spread. People who are exposed to a greater amount of virus are more likely to get sick. In 1918, many cities illegalized spitting in public and there was minor outrage as people were arrested for spitting. But the fact is that the less spit and snot and mucus that we come in contact with, the less likely we are to get sick.
I haven’t heard people talking about the main reason why I wear a mask. When I have it on, I’m much less likely to rub my nose. I have constant allergies and constant itchy nose AND I’m a terrible face-toucher. When I’m wearing a mask it not only stops me from touching my nose directly, it reminds me not to rub my eyes either. In that way, the mask helps prevent the main method of transmission: touch.
With these transmission methods in mind, let’s talk about social response to the virus. We responded much better to coronavirus 2019 than we did to influenza 1918, there is no question. The 1918 response feels like a car crash in slow motion. Let's take a look at examples of pandemic response and their outcomes.
Influenza is another example of ancient conceptions of medicine in our modern language. It refers to the influence of the stars on human health. Humans have suffered influenza epidemics since as early as 1510. Since that time influenza epidemics and pandemics have become increasingly common, probably because we have been traveling the world faster and in greater numbers than ever. At least three flu pandemics hit Europe in the 18th Century and at least 4 in the 19th. A major pandemic hit in 1889 which offered some immunity to its survivors in 1918. Studies on immunity to the 1918 virus also revealed that another flu pandemic had created partial immunity which could not be attributed to any of the known pandemics, meaning that even more flu pandemics happened in the 19th century than we noticed. The summer wave of flu in 1918 had been surprisingly deadly, peaked, and then receded. It was now autumn.
John M. Barry in his book The Great Influenza describes outbreaks at army bases around the world in the fall of 1918 as being like the bubbles that form when a pot of water is on the verge of boiling. As the temperature rises, first you see a few spots start bubbling from the bottom of the pot before the whole thing breaks into a boil. For the reasons discussed earlier, the Army bases were uniquely vulnerable to fostering and spreading disease. Starting in August they started seeing the more extreme symptoms I described in the last section. By September, even the best army hospitals were overwhelmed. At Camp Devens, near Boston, fifteen hundred soldiers reported ill on the same day. On September 22, 19.6 percent of the entire camp was on sick report. Hospitals were literally full to overflowing. The Devens hospital, which could hold at most twenty-five hundred patients, was caring for six thousand. The nurses did all they could to fight against the flood of blood and mucus coming out of patients but all their efforts couldn’t keep the hospital sanitary.
Camp Devens proved to be, sadly, typical of the situation within army bases and it was only a matter of time before their pandemic spilled over into the general population. Philadelphia in 1918 was an overflowing industrial city. The immigration of industrialization had been accelerated by the war and men were drawn from the surrounding areas to work in new munitions and weapons factories. Often several families were living in the same 2 or 3 bedroom flats and men would sleep in the same bed in shifts around their working hours. This was the tinder.
Then came the spark, which wasn’t so much a spark as an already lit torch. As was typical in 1918, the mayor of Philadelphia did nothing to prepare for the influenza plague other than insist that it would not be a problem. There were already hundreds of sailors hospitalized in the city and over a thousand dead in Boston. The medical board advised the population to stay warm, keep the feet dry and the bowels open, drawing on ancient medical remedies. But the war raged on and the American war effort ran on bonds. To raise the necessary bonds, parades had been organized to mobilize the people. The Philadelphia Liberty Loan parade was scheduled for September 28.
By September 26th there were now fourteen hundred sailors hospitalized with influenza. On the 27th, 123 civilians were admitted to the hospital. Pressure rose from all corners to cancel the parade. The latest round of draft had already been canceled for health reasons and medical professionals the country over were demanding that all public gatherings be canceled. Instead Philadelphia proceeded. On September 28th, two miles of paraders filed down the street including marines, sailors and soldiers, and then spent the rest of the day shopping and socializing with the hundreds of thousands of civilians who came out to share their patriotism.
Within seventy-two hours, every single bed in each of the city’s thirty-one hospitals was filled. Soon, the city’s daily death toll from influenza exceeded the weekly death rate from all causes combined. City authorities and newspapers continued to insist that all was well even as measures like a ban on public gatherings went into effect. The newspapers reported that the city had reached the peak of the crisis on October 5th, 6th, 7th, and 8th as the daily death toll doubled from 200 to 400 and then doubled again. Finally, on the 10th, the daily deaths peaked with 759 citizens dying in a single day. All work had stopped in the city; people were too scared to go outside. This was the fire.
Hospitals had long since been overrun with sick and now there was no way to get help. Even the doctors and nurses were falling ill and dying in droves. The ill had to rely on family or friends for nursing, if they had any who were well enough to do so. The lack of care doubtlessly killed in the thousands and worse still, now people were dying in their own homes. The city became choked with bodies. Even daily carts taking the dead to mass burial sites couldn’t keep up. The supply of coffins had long since run out and the idea of a private funeral became unthinkable. Hospitals piled the dead up like cordwood, ten bodies high. Inside of most houses in the city were one or more corpses slowly putrefying. These were the survivors’ parents, children, teachers, preachers, doctors, employers and employees.
Meanwhile, the war marched on. Blaming Germany for the pandemic became common because it was considered patriotic. We saw an echo of that in President’s Trump’s focus on blaming China for the disease. The white house acknowledged the violence it was inciting against Asian-Americans and stopped calling this pandemic “china flu” on March 23rd. The federal government and armed forces had spent most of the year turning the American economy into a machine for making war materiel and soldiers, and that process could not easily be reversed while the war continued. Men continued to shuttle to the east coast in close, confined trains and then board tightly packed ships. Although the latest round of the draft had been canceled because of the disease, the troop movements continued and continued to spread disease. Despite the military’s halfhearted attempts to screen sick men, the troop transports became increasingly deadly.
Within 48 hours of leaving port the massively overcrowded troop ships filled with coughing and sneezing. Closed, steel spaces with inadequate ventilation meant that there was nowhere to hide from the virus. Then the hemorrhaging began. Blood pooled on floors and ran down corridors. In rough water, blood splashed on everything, clothes, faces, and the bodies that now lay in every compartment and corridor. Eventually the dead were given perfunctory funerals before being thrown into the sea. Ships arrived in Brest, France with their sailors exhausted and decimated, already traumatized.
Still the movements continued. In the trenches, American soldiers died from influenza and fighting at the same rate and yet still more sick men were being sent in. At the beginning of October, the Austrian government sought peace on any terms. At the end of October, the Kaiser handed over power to a new Republican government. As discussed in the last podcast episode, this was in part a plot to frame the new Weimar republic for the failure of the war. President Wilson made no public statement about influenza, nor did he divert any of the war economy to fighting it. He did summon the chief of staff of the army to discuss the issue of shipping men to France. General March replied that any sign of hesitation might cause the Germans to withdraw from the negotiating table and that quote “Every such soldier who has died just as surely played his part as his comrade who died in France.” This actually makes sense given the WWI logic that they were more attempting to deplete the other countries than conquer territory. For a month the death ships continued making the Atlantic passage until the war formally ended on November 11th.
In October, panic set in across the country. Schools, cities, and governments shut down. Meetings were held outside if necessary and the gauze mask became virtually ubiquitous. The Red Cross warned that “the man or woman or child who will not wear a mask now is a dangerous slacker.” Throughout the U.S., people living in isolated areas starved as surrounding communities refused to transport food out of fear of catching the virus. Desperate doctors prescribed treatments they knew would not work—like vaccines and serums for other diseases—and long-debunked treatments. We are seeing an echo of this in the President’s insistence that a proven-dreadly combination of phamacudicals can fight off coronavirus infection. Blistering with mustard plaster, purging with mercury chloride and even bleeding veins all made a comeback. New treatments were devised such as attempting to turn the body alkaline because the opportunistic bacteria have a harder time surviving in alkaline environments. As a side note, do not attempt this, the body is very good at regulating its pH and if you do manage to change your pH, it means something has gone very wrong. Soldiers were given antiseptic mouthwash and had disinfectant sprayed into their nose and throats. It reminds me of a recent suggestion by the President of the United States that coronavirus could be fought with an injection of disinfectant to the infection site. Unfortunately, none of these methods cured the disease. Only nursing, pneumonia treatments, and quarantining had any effect.
New York City was the hardest hit and continued to experience influenza deaths after the disease had died out in most parts of the world. Constant immigration allowed the disease to smolder like a fire being fed new fuel. Politics made this worse. Starting in January of 1918, Tammany Hall made a concerted effort to reclaim the city government by replacing appointed positions with loyal men. In a few short months, they had replaced most of the health board, which had been a world-class institution, with men of no medical distinction led by a homeopathic doctor without an M.D.. The Tammany machine would later elevate this “doctor”, Royal Copeland, to the senate. A flood of criticism from health officials forced Copeland to resign, but New York went into the crisis with demoralized and ineffective health leaders, which contributed to the deaths.
The U.S. and Europe weren’t even the hardest hit by the virus. At the beginning I mentioned that disease can be classist. This is true on a world scale too. India, in particular Mumbai, was hit hard, as was China and southeast Asia. Barry estimates that around 5% of the developed world died while around 10% of the developing world did. We see the same pattern, hardest hit places were the most overpopulated and near centers of travel.
So, quarantining, it seems, is the best guarantee of survival. People tended to fare better in the less-populated west. Coloradans were particularly strict with their quarantines. Ouray, Colorado set up a shotgun quarantine, refusing access to all outsiders but were still hit by the flu. Silverton shut down before a single case was reported but they still suffered as well. Gunnison, however, a larger town and a transfer hub for rail traffic, was spared. They blocked off the roads to and from town and informed train passengers that if they stepped off the train for any reason, including a cigarette, they would be spending a week in the town jail. Monument, another Colorado town, closed down all retail shopping. Groceries could be ordered by shouting through the windows to be picked up at the door.
Places that managed to delay the onset and flatten the curve of sickness experienced less death. San Francisco’s ordinances had been so strict and effective that they saw only a fraction of the death that visited the similar city of Los Angeles. So much so that on November 21st they announced the end of the ordinances, people took off their masks, and went back to work and to the movies. It’s hard to know how much the third and fourth waves of illness were caused by behavioral changes and how much was the natural cycle of the virus. It is clear that effective quarantines can create firebreaks that stop the illness from circulating endlessly.
Partly at the urging of the Anti-Mask League, the so-called “onerous” restrictions were dropped and San Francisco saw another two thousand of its citizens die before the end of the year. It was ultimately one of the hardest-hit cities in the U.S.. Denver is another city that acted fast, banning public gatherings and flattening the curve. By Armistice on November 11th, business leaders had decided they’d overreacted. Restrictions were lifted and by November 22nd, deaths were higher than ever. Even as city officials tried to reinstate restrictions, city business owners protested at the capital, fearing to lose even more money. Ultimately, citizens were unwilling to endure another period of quarantine and deaths in Colorado, despite all the measures I’ve mentioned, had a higher death rate than the national average.
I live not far from that capitol building and got to witness a very similar protest a few weeks ago. I saw signs saying things like “I need a haircut” and “I want to go shopping” as the death toll from coronavirus rose day after day. If we are to take anything from our last experience with pandemic, it should be that opening up restaurants and bars right now would be the best way to ensure continued deaths throughout the rest of the year. As Dr. Faucci has said “if it looks like you’re overreacting, you’re probably doing the right thing. At this point, reopening too quickly risks undoing all the good that quarantine has done so far.
The H1N1 influenza continued to kill throughout 1919 and into 1920 at lower rates as it circled the globe again and again. It seems that the virus reached its peak of lethality in the fall or winter and then went back to being less lethal. This can happen when a virus passes through several hosts. For example, ebola when passed from human to human becomes less lethal. The coronavirus, when passed from bats to humans can be imperceptible. Current theories suggest that it gained its lethality by passing through a pangolin population before transferring to man.
Perhaps its last casualty was peace. Throughout 1919, President Wilson attended the peace conference in Paris. In fact, despite the United States' late entry, he found himself at the center of the conferences. The French and British delegations seemed intently focused on punishing Germany. Wilson felt strongly that there would be “no peace in victory” and that the treaty’s first priority should be ensuring a long-lasting peace. Then he came down with influenza. Some reports and even histories claim that this was a stroke (Wilson had strokes before and after this time) but he was confined to his bed with flu for several weeks. Future president Herbert Hoover was working with Wilson in Paris at the time and wrote “Prior to that time, in all matters with which I had to deal, he was incisive, quick to grasp essentials, unhesitating in conclusions, and most willing to take advice from men he trusted… [Now] others and well as I found we had to push against an unwilling mind.” His aides commented that Wilson was never the same after the illness. Suddenly, Wilson stopped fighting and conceded to Clemenceau that the Rhineland be demilitarized, the rich Saar coal fields would be given to France, Germany would bear full responsibility for the war and pay for all countries’ debts. All of these would be major talking points for Hitler’s revanchism. Germany’s colonies in Africa were given to Italy and in Asia to Japan, setting the stage for the Axis alliance of world war two. Wilson left Paris not long after, saying “If I were a German, I would not sign it.” He was never able to get the centerpiece of his plan, an international community called the League of Nations, passed by congress and the body found itself toothless without American support.
I am happy to report that there were positive results from the 1918 flu too, mostly in medical science. Much research was directed at a bacteria called B. influenzae, still considered the prime suspect as the pathogen causing influenza. For a decade, better and better techniques for isolating bacteria and creating agur conducive for their growth were discovered. One of the scientists experimenting with B. influenzae, Alexander Fleming, in September of 1928 (almost exactly a decade after the pandemic) discovered that a sample of Staphylococcus wasn’t properly covered and a fungus from the open air had killed it off. Fleming cultured the fungus and discovered it was penicillin and suggested that it could be used as a clinical solution for bacterial infections. In the 1930s, intravenous solutions were devised and by the 40s we had a new tool in our war on bacteria: antibiotics.
Ironically, the bacteria he’d been experimenting with Staphylococcus, is quickly becoming the most common antibiotic-resistant infection. This is partly the result of overprescription of antibiotics in humans, partly due to patients not finishing their full course of antibiotics (leaving any bacteria alive ensures that the survivors are the most antibiotic-resistant), but is mostly because livestock are dosed with huge levels of antibiotics to prevent infection in the close, unsanitary conditions in which they are kept. 70% of antibiotics used in America go to livestock. An obvious starting point to fixing this would be to keep chickens, pigs and cows in more sanitary conditions with less crowding.
Another major discovery to come out of the 1918 pandemic has to do with genetics. Through the first half of the 20th century, science had accepted that the process of natural selection described by Darwin and the system of genetic inheritance described by Mendel could explain evolution, but the actual substance that transmitted genes was not yet known. Oswald Avery was a researcher who strongly believed in the bacterial origin for influenza and doggedly worked toward understanding it for decades after his colleagues moved on. When the influenza virus was discovered in pigs in 1936, his research veered towards the immune system. It was known that the worst of the damage of influenza came from the immune system itself attacking the cells of the body. Avery discovered that this reaction was triggered by bacteria in cell casings but not the cell casings or the bacteria themselves. Through a painstaking process of elimination, he discovered that bacteria without cell casings could gain them when introduced to a certain carbohydrate. This went against the intuition of the time. Genes were complex things that clearly needed many variables to pass on such complex information and therefore the medium of genes was assumed to be protein. In 1944 he published a landmark paper proving that genetic information was passed via a polymer called Deoxyribonucleic acid. A decade later, Watson, Crick and Rosalind Franklin discovered the structure of DNA and described how just two sets of two chemical pairings can encode an entire genome, opening the door to modern genetics research.
From my investigation into the history of pandemics I’ve come away with this: of all the measures a person can take, in this case, the oldest is the most effective. Social distancing, for the trouble it causes, works and a quarantine works even better. We are lucky in that we have a choice. In Boston, Philadelphia, New York and other major cities, the economy shut down not due to public officials but due to death and fear. The paucity of firebreaks and containment allowed the virus to kill for years after 1918. Additionally, it’s not just the deaths we need to worry about. People who get so sick that they almost die are often changed, weakened for the rest of their life.
As I said at the beginning, the Denver newspaperwoman Katherine Anne Porter was haunted by her experience with death for the rest of her life. Quarantining efforts only have an effect as long as they are continued for the entirety of the outbreak, or else you have just delayed the onset of the sickness like San Fransisco did. The height of pandemic, the point that we are at now, is not the time to stop fighting. Let’s honor our work so far and honor our elderly members of society by making sure we kick this virus’ butt. If not, we risk it recombining with other coronavirus strains currently circulating which could cause a second, more deadly wave.
The final note I want to touch on is information and misinformation and disinformation. Spanish flu got its name from the only country that was willing to talk about it. Throughout the U.S., public officials and newspapers insisted that the only thing to fear was fear, that being afraid would only cause more death. As they continued assurances that everything was getting better in the midst of the peak of death, they lost credibility. A deeper panic spread, the panic of not knowing what’s going on, one that left isolated communities without supply and left patients alone in their homes with no one to nurse them. Katherine Anne Porter was one of the lucky ones, she was treated in a hospital and survived. There were thousands who could not find help and died. Furthermore, in both the 2003 SARS and the 2009 H1N1 outbreak, early and correct information helped put the right measures in place and stopped the diseases from having the same kind of effect that our current coronavirus pandemic is having. I see an echo of 1918 in the communication we saw from world leaders during this crisis, especially in America and the UK, urging people to not take precautions. When you take precautions, you are not living in fear. You are living in fear when thousands of your countrymen are dying every day and your leaders continue to lie and say that things are all right. Things are not all right. When one hundred thousand of your countrymen die over the course of a few months, that’s not all right. It’s a tragedy. As the New York Times said, it’s an incalculable loss. But it’s nowhere near as bad as 1918. We have all the tools and knowledge we need to bounce back from this. We do not need to wait for a vaccine but we do need to wait for the worst to pass and then ease off of quarantining slowly. We live in an age where many of us can work from home, shop online, and stay in close contact with our friends and family virtually. Our burden is a tiny fraction of what our ancestors survived. We can defeat this pandemic and know that our actions saved the lives of our most vulnerable countrymen. It’s our patriotic duty, not just to our country but to our species. I’m Peter McGuire and this has been my unlikely explanation.
Selected Sources
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5538214/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4790547/
Strong, early, and prolonged response works https://jamanetwork.com/journals/jama/fullarticle/208354
The Great Influenza, John M. Barry
The Social Transformation of American Medicine: The Rise of a Sovereign Profession and the Making of a Vast Industry, Paul Starr
