What If the Plague Lasts a Hundred Years?
Skills, knowledge, and organizations all change, but human vulnerability to disease does not. Infectious diseases, which existed before the first humans, will always be with humankind and, as ever, remain one of the basic parameters and determinants shaping human history.
——Adapted from William H. McNeill, Plagues and Peoples
Many people are lamenting the hard years of the past three. I have compiled plague history from the records; I have never seen a great plague era last less than a hundred years, and three years is but a small prologue. When great plagues struck in history, the common result was nine empty houses out of ten and wailing refugees everywhere.
With modern science and technology, such horrors should not recur, but the impact of a long-drawn plague on social productivity and the destruction of social order will be profound. In the first quarter of this year, U.S. productivity fell to its lowest level since 1947; over twenty million Americans now live on borrowed money; the French recently cleared supermarket shelves to hoard supplies; Japanese, hit by inflation and the falling yen, now dare not even eat soba noodles, their favorite, in excess; UN statistics show that after the epidemic the number of hungry people worldwide is nearly 200 million; and our country’s second-quarter economy will also be greatly affected.
As viruses circulate, they usually recombine their genes with other viruses to form chimeric viruses; the new chimeric viruses keep breaking through the immune system, causing wave after wave of infection. A new wave may sweep the globe again this summer and autumn, and in the fourth quarter the pressure on our country to prevent imported cases will peak once more. Because of our prevention policy, the shock we feel usually lags by about a quarter.
From the standpoint of infectious disease epidemiology, any city with a population over 500,000 is a breeding ground for contagious disease. Once a new infectious disease appears in such a population center and is not detected and stopped early, it is very hard to contain and can easily become a global pandemic.
In the early nineteenth century the world population was only about 1 billion, and there were only about 10 cities of over 500,000. Today the global population reaches 7.8 billion, there are 18 megacities of over ten million, Tokyo alone has nearly 40 million people, and cities of over 500,000 are too many to count. This is a situation humankind has never faced before, and the risk of pandemic is correspondingly unprecedented.
For more than a hundred years we have been full of confidence in human science and technology; before the epidemic, even medical textbooks said that deaths from infectious disease were no longer the leading cause of human mortality. Before COVID struck, our investment in the prevention and control of infectious disease was pitifully small. Now we are paying a heavy price for this arrogance and neglect; if time could be turned back, many countries—by investing just one-tenth of the economic loss caused by COVID into the prevention of infectious disease—might never have had a pandemic at all.
From the virus’s own point of view, COVID-19 is a near-perfect virus. It is an RNA virus that mutates frequently and now circulates in many mammals, humans included. It constantly splices in the genes of other viruses widespread across the mammal kingdom, forming new variants and repeatedly jumping between species. How it will mutate in future we cannot yet predict.
True, it may mutate to become less and less virulent, but from the history of human plagues, not every pandemic follows that rule. The plagues of the late Han, late Yuan, and late Ming came wave after wave, with very high case fatality; the long-drawn outbreaks reduced populations in some places by over 80%. When medieval plague swept Europe, it too came wave after wave, killing two-thirds of the people. This fatality rate is similar to what Zhang Zhongjing, author of the Shanghan Lun (Treatise on Cold Damage), recorded for his own clan, which lost two-thirds of more than two hundred members to plague within ten years.
If, ultimately, the COVID virus as the fuse causes the global population to fall by more than two-thirds over the coming century, I would not be surprised. Malthus’s population theory is not outdated: overbreeding leads to overpopulation, plagues and wars then cut the population, and people voluntarily lower their willingness to bear children. It takes two Earths to support 7.8 billion people; our population must be cut by at least half to balance resources and environment.
We often say there were once four great ancient civilizations, of which China is the only one that has survived to this day; the others have all perished, for reasons no more than plagues, wars, and natural disasters—of which the plague is the most lethal. After Europeans discovered the New World, they brought smallpox to the Americas, where it had never circulated, and great numbers of Indians died of the plague; this was more terrible than any weapon.
Since written records began, China has always been one of the world’s population centers, and the plagues in our history are too many to count. Many of the plagues that once swept the globe even originated in China, which is one of the world’s four great plague cradles. The reason is simple: our country is vast and resource-rich, populous, and biologically diverse, so cross-species transmission of pathogens happens easily here, making it a cradle of infectious disease. Then why has the Chinese people escaped the plagues and survived to this day? It may have something to do with our culture; plagues have left a deep imprint in our cultural genes.
We often say the Chinese are a model of thrift and household management, with a sense of preparedness in times of peace; Chinese love of saving is famous the world over. The Chinese are also more self-disciplined, and more family- and community-minded, than other peoples. Individualism has little market in China; European and American culture has been imported for years, yet the individualism that runs rampant in the West has still not taken root here. A large part of the reason is the influence of plague: China has been repeatedly struck by plagues in history, yet our line of descent has always survived, and this is no accident. When a great plague strikes, people can avoid genocide only through collective self-discipline and mutual aid. In collective self-discipline and mutual aid, of all the peoples of the world, none surpasses the Chinese.
Still, this Chinese spirit of collective self-discipline and mutual aid also brings drawbacks. Modern people who prize individual freedom are deeply displeased with Chinese compliance, criticizing it as slavishness and giving dictators an opening; modern people who prize consumption are likewise displeased with the Chinese habit of saving, criticizing it as a peasant mentality that holds back economic development. But once a plague strikes, we come to appreciate the benefits of communal consciousness and of the saving habit that prepares for rain. We often say that many hardships make a nation strong; in the subconscious of a Chinese people weathered by disasters, there lies a cultural gene of preventing catastrophe.
Before nature, the power of the individual is always negligible. Since humans walked out of the African savanna, struggling against countless hardships along the way, what has brought us to today is precisely our capacity for group cooperation; no lone hero fighting alone can save humanity. If science and technology are not combined with human capacities for group cooperation and self-discipline, they cannot do much to improve human welfare.
I can boldly imagine that over the coming hundred years, human society will look very different from today because of a long-drawn plague. Although peoples across the globe now squabble like a boiling pot, in the end we will join hands against infectious disease, because the very nature of contagion means no one can stay untouched. The human population will be effectively controlled, and births will keep declining until they reach a new turning point—only when human existence is no longer so hard will people be willing to have more children. Round after round of infectious disease will also cull many compatriots with poor vigilance and self-discipline, and the civilization of the future will be more advanced than today. Our public-health systems will grow ever more developed, and city planning more rational, no longer so crowded as now.
As individuals, only by adapting to the new situation, adjusting our living conditions and psychological expectations, striking a reasonable balance between saving and consumerism, and raising our vigilance and self-discipline, can we survive the wave after wave of infectious disease to come. Any hope that infectious disease will vanish entirely is unrealistic; a moderate fear of nature helps us survive, because danger is always objectively present, and no one can live in an absolutely safe environment.
Only when both groups and individuals act can we reduce the death toll in a terrible plague. Reducing population through natural death and fewer births is always more acceptable than cutting it through war and plague.