IT IS KNOWN as the Next Big One (NBO), the virus that will scythe its way through populations leaving millions dead in its wake. The one that cleaves history into a before and after. It is a rare occurrence but all it takes is one rogue strain of virus that mutates. The science writer David Quammen in his book Spillover has a portion on the Next Big One where he makes a brief recount of the earlier big ones. The most recent is still alive: AIDS. It might surprise some today that HIV, the virus that causes AIDS, is clubbed among pandemics because they don’t remember the global panic of its beginning in the 1980s. We just got used to it and, even if a cure was never found, there was containment. HIV takes its toll even now but in a slow extended curve. Quammen says in the book that AIDS has so far killed 30 million, and 34 million are infected. His book came out about eight years ago and the numbers have only increased since by a few millions. He also mentions polio, the virus that stands out for attacking children. There is the biggest of them all, the Spanish Flu of 1918-19, even though it had little to do with Spain. But half a millennium earlier, when the Spaniards went and conquered the American continent, they took with them the smallpox virus which decimated the indigenous people who had no immunity against it. The virus made possible for a handful of adventurers in a few years to destroy an entire civilisation. And just before that in Europe, the bubonic plague was so devastating that it killed 30 per cent of the population. Quammen writes: ‘Moral: If you’re a thriving population, living at high density but exposed to new bugs, it’s just a matter of time until the NBO arrives. Note that most of these big ones but not all of them [plague the exception] were viral. Now that modern antibiotics are widely available, vastly reducing the lethal menace of bacteria, we can guess confidently that the Next Big One will be a virus too.’

The NBO only exists in relation to humans. Since we are in the business of living, we try to make sense of what is trying to kill us. The virus neither plans it out, nor is it aware of its own potency. It only takes what is offered and, with the progress of human beings out of caves, much was on offer. Before humans took ownership of the earth, there couldn’t be a pandemic because as hunter-gatherers living in small groups and separated by long distances, the virus’ journey ended with the last human it killed. But then agriculture was discovered and a nomad species became sedentary, group sizes steadily increased. A new category called ‘crowd diseases’ came into being, like smallpox, measles, tuberculosis, influenza, etcetera, which spread like wildfires into a forest of men and women. Epidemics and then pandemics became possible. Jared Diamond points out in the book Guns, Germs, And Steel that many of these crowd diseases are young. ‘[They] could have arisen only with the buildup of large, dense human populations. That buildup began with the rise of agriculture starting about 10,000 years ago and then accelerated with the rise of cities starting several thousand years ago. In fact, the first attested dates for many familiar infectious diseases are surprisingly recent: around 1600 B.C. for smallpox [as deduced from pockmarks on an Egyptian mummy], 400 B.C. for mumps, 200 B.C. for leprosy, A.D. 1840 for epidemic polio, and 1959 for AIDS,’ he wrote.

WITH FIXED ADDRESSES, humans created conditions that new germs liked, such as sewage near places of residence that allowed microbes to jump into drinking water. There were also other new modes of transmission, like rats that gathered around food, mosquitoes, etcetera. With cities, humans became so densely packed that Diamond terms it a ‘bonanza’ for microbes but it was not the only one. There was also the leap in the ability of humans to travel, even cross continents. Diamond wrote, ‘Another bonanza was the development of world trade routes, which by Roman times effectively joined the populations of Europe, Asia, and North Africa into one giant breeding ground for microbes. That’s when smallpox finally reached Rome, as the Plague of Antoninus, which killed millions of Roman citizens between A.D. 165 and 180. Similarly, bubonic plague first appeared in Europe as the Plague of Justinian (A.D. 542-43). But plague didn’t begin to hit Europe with full force as the Black Death epidemics until A.D. 1346, when a new route for overland trade with China provided rapid transit, along Eurasia’s east-west axis, for flea-infested furs from plague-ridden areas of Central Asia to Europe. Today, our jet planes have made even the longest intercontinental flights briefer than the duration of any human infectious disease… when the human population became sufficiently large and concentrated, we reached the stage in our history at which we could at last evolve and sustain crowd diseases confined to our own species. But that conclusion presents a paradox: such diseases could never have existed before then! Instead, they had to evolve as new diseases. Where did those new diseases come from?’

New diseases arose because viruses began to jump species from animals and birds in proximity to humans. In the case of Covid-19, it is thought to be either through bats or pangolins, or a route that involves both of these Share this on

The answer to that question leads us to Covid-19. The new diseases arose because viruses began to jump species from animals and birds in proximity to humans. In the case of Covid-19, it is thought to be either through bats or pangolins, or a route that involves both of these. Meanwhile, a major difference arose between pre- and post-20th century—with the discovery of antibiotics that kill bacteria, pandemics became almost exclusively viral. Recent ones—from AIDS to SARS to Covid-19—are all by viruses. How prevalent were virus pandemics earlier in history? We aren’t sure because viruses themselves weren’t known. Even the 1918 Spanish Flu was initially thought to be caused by bacteria because whenever medical scientists looked in the microscope at samples, they only saw bacteria that were attacking the weakened immune systems of patients. Ignorant about viruses, they made the wrong conclusion.

The Spanish Flu is called the mother of all pandemics. It is what happens when the worst-case scenario comes true. Everytime there is a new virus like Covid-19, the question at the background is whether this will be another Spanish Flu. It killed at least 50 million people and some estimates put the number as high as 100 million. In India alone, it might have killed 18 million people. A combination of factors came together to make it the most-deadly pandemic ever. It started from an army base in the United States towards the end of the First World War and quickly spread to the rest of the world. It reached Bombay in May 1918 but as a milder strain, not unusually fatal. But then came a second death wave in September that year with the virus having mutated into a more vicious form. It spread at blistering pace through a country ravaged by drought with its people immunologically weakened.

Two years ago, when it was the hundredth year of that pandemic, I spoke to Laura Spinney, author of Pale Rider: The Spanish Flu of 1918 and How It Changed the World. She said that even though there had been at least 15 flu pandemics in the last 500 years, the Spanish Flu still needed a separate explanation for its extraordinary toll and that was a world war. “The so-called Russian Flu of the 1890s, which was the previous flu pandemic, killed in the region of a million people. We have had three flu pandemics since 1918, none of them have killed more than about 2 million. The Spanish Flu killed at least 50 million. It is a huge anomaly that we have to explain. The reason people think is there was some kind of terrible synergy between the flu and the war. The flu emerges, a new strain, and it emerges into a world at war. That means, for example, there are lot of people on the move. There are particular conditions you wouldn’t find outside of that particular war. You have hundreds of thousands of young men packed into the trenches on the Western front. In a peacetime situation, the optimal strategy for the flu virus in evolutionary terms is to moderate its virulence. When it bursts out, it doesn’t know its host, it has not adapted to humans very well. It tends to be very virulent. But it moderates that virulence over time, eventually becoming a seasonal flu strain. It is in its interest, if you think about it, in evolutionary terms, in survival terms as a species, to keep its host alive long enough so that the host can move about and infect other hosts. That is why you see a pandemic recede even if no measures are taken to interrupt its course or contain it. And eventually that pandemic strain becomes a seasonable strain,” she said.

But by then the damage has been done and the impact is lasting and momentous. The New Yorker recently interviewed Frank M Snowden, author of Epidemics and Society: From the Black Death to the Present. A Yale professor who specialises in the history of medicine, he spoke of how epidemics shaped the modern world because they made human beings think of the big questions. ‘The outbreak of the plague, for example, raised the whole question of man’s relationship to God. How could it be that an event of this kind could occur with a wise, all knowing and omniscient divinity? Who would allow children to be tortured, in anguish, in vast numbers? It had an enormous effect on the economy. Bubonic plague killed half the population of full continents and, therefore, had a tremendous effect on the coming of the industrial revolution, on slavery and serfdom. Epidemics also, as we’re seeing now, have tremendous effects on social and political stability. They’ve determined the outcomes of wars, and they also are likely to be part of the start of wars sometimes. So, I think we can say that there’s not a major area of human life that epidemic diseases haven’t touched profoundly,’ he said in the interview.

THE SPANISH FLU, for example, is said to have contributed to the Indian independence movement. Spinney says that for historian AJP Taylor, it was the moment when Indians turned en masse against the British because their handling of the pandemic had been inadequate. Also, with most of the doctors at the warfront, the British were forced to seek assistance from local caste and community organisations for relief measures, a mobilisation that spilled over to the freedom movement. Spinney said, ‘Certain historians argue that it mobilised the grassroots and connected it to the national movement.’ The Spanish Flu might have even been a factor for the Second World War three decades later because when peace negotiations were underway in Paris after the First World War, US President Woodrow Wilson’s health began to deteriorate and, given the timing and symptoms, Spanish Flu is a possibility. And the theory goes that Wilson was the voice for a moderate peace but his weakening health condition could have led to the harsh terms forced on Germany by the other victors which then led to Hitler.

Can Covid-19 be the Next Big One? It transmits fast but doesn’t kill in a high degree. It could mutate into a more vicious strain like the Spanish Flu but what humanity has at its side is experience and organsiation. We have never been more prepared at dealing with pandemics. Nations and global health organisations are ready now with measures to be implemented the moment they realise a pandemic is on the loose. Even if there is no cure, the spread can be stemmed because we now have the ability to quarantine vast numbers of people until a vaccine becomes possible. The pandemic virus will still take a toll but not at the scale that it used to.