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Reducing the Chance of New Pandemics

It has been months since the novel coronavirus hit Western countries, and many are now wondering how and when normality will return and what a new normal might look like. Some expect that a second wave of infection will be avoided by seasonal properties inherent in the virus, while others contend that this will only happen if strong action is taken to contain it. Some expect that a vaccine will allow a rapid return to the world we had before, while others argue that even if such a vaccine were to be developed, it would permit no such thing. Absent from many of these discussions is how to avoid another situation like this one.

The argument can be framed in simple economic terms or in more complex terms related to existential risk and the very future of our species on Earth. The current pandemic is estimated to have cost nations on average a third of the world’s GDP—over 30 trillion US dollars—so spending billions on even a marginal reduction of the probability of another such event is likely to be worth it. The existential argument involves thinking about catastrophic consequences and taking risk asymmetry seriously. These are explored in detail by Nassim Nicholas Taleb and his coauthors, by Toby Ord in his recent book The Precipice, and by the Effective Altruism group 80,000 Hours in their analysis of global catastrophic biological risks. In what follows, I will focus on how we might prevent the next pandemic, rather than why.

To call SARS-CoV-2 the “pandemic of the century” is a figure of speech, and an optimistic one at that. In fact, we have detected far more pathogens with epidemic or pandemic potential than usual in recent years: the 1968 Hong Kong flu pandemic, HIV, Dengue, Lassa virus, SARS, MERS, swine and avian influenza, Zika, Ebola, and several others. One might fairly wonder whether this represents better detection of novel diseases or a genuine increase in risk—that something about the world of 2020 makes it more vulnerable to pandemics than in 1920 or 1820. In light of at least one clear precedent, and the many factors that causally contribute to an increased risk of emerging diseases, it is hard to escape the disturbing conclusion that the latter is the correct view, and that emerging diseases have increased even when we adjust for reporting bias, including figures for decade trends.

This has happened before

The most familiar example of new pandemics resulting from societal change is what historians call the Columbian exchange, the process by which flora and fauna were transferred between the Americas and the Old World during the period of European colonisation. Infectious diseases were among the gifts each side of the Atlantic bestowed upon one another: Europe famously may have contracted syphilis from the Americas, but the Americas came off worst, with smallpox destroying perhaps as much as 95 percent of the pre-Columbian population by the middle of the 17th century.

Perhaps the clearest example occurred even earlier. Calling agriculture the worst mistake in the history of the human race is unserious, but we can be reasonably confident that this development made things easier for existing pathogens and allowed for the emergence of new ones. This is because many pathogens are zoonotic—capable of infecting animals like cattle as well as humans—and farming presents not only more interactions with livestock, but a new breeding environment which in itself can help mutations that wouldn’t otherwise succeed. This remains the case today: We know zoonotic pathogens are over-represented in emerging diseases.

In his sweeping thesis Against the Grain, James A. Scott demonstrates that population growth nearly froze in the 5,000 years following the widespread adoption of the agricultural lifestyle, with a global population of four million people in 10,000 BCE rising to only five million by 5,000 BCE. That period, Scott argues, produced some of the highest mortality rates our species has ever experienced as the frequency of epidemics skyrocketed. Population density was certainly a factor (a ten-to-twentyfold increase over what was typical of a nomadic hunter-gatherer lifestyle), as was close contact with domesticated animals.

Once population growth recovered, population size itself contributed to pathogen prevalence. Crucially, there is a parameter in epidemiology called critical community size. This refers to the population size needed to sustain a disease given its properties of spread, lethality, duration of immunity, etc. Measles, for example, is believed to have originated from rinderpest virus, a highly virulent cattle disease that was only eradicated 10 years ago. The critical community size of measles is close to half a million—and since there have not been half a million people living in close proximity for much of our evolutionary history, that means it must be evolutionarily recent. Later research has confirmed this hypothesis, and disagreement only remains about whether it started spreading within the last thousand years or as far back as the sixth century BCE.

Many other diseases seem to follow this pattern, even if much of the research is still preliminary. Tuberculosis is believed to have arisen 6,000 years ago from Mycobacterium bovis due to early farming. Likewise, cholera’s evolution is attributed to life in river deltas, where fresh and saltwater mix, providing a perfect breeding ground for both its safe ancestor and the more familiar, lethal version. Yersinia pestis, of black death fame, is more controversial but still believed to have originated in ancient, not prehistoric times. The fact that we now have vaccines, antibiotics, and other means of controlling the diseases on this list should make us both proud and alert; without human intervention, immunologically naïve populations can be devastated by diseases like measles and something similar can be expected to occur as a result of other novel pathogens.

The plurality of historical examples should convince us that what we might call the general lifestyle of our species (if not simply economic development) has already offered many new pathogens the chance to prey on humanity at least once. We are now better connected and more tightly networked than at any point in human history; indeed, a scientific paper has already argued that SARS-CoV-2 spread so much more rapidly than SARS-CoV-1 partly because many more planes, workers, and tourists now leave China than they did even 17 years ago, while global population size has obviously also increased substantially in the same time period. It should be obvious that the reversal of economic globalization and population growth would also likely involve and result in enormous suffering. Fortunately, there are many other ways to reduce the chance of new pandemics. Even better, they may have additional beneficial effects for humanity and the planet.

The food supply chain

The virus that causes COVID-19 has been attributed to the infamous wet markets in China, and culinary practices in which eating wild animals like bats is not alien to at least a fraction of the population. This is both fair and unfair. It is fair because, as Dr. Christian Walzer of the Wildlife Conservation Society put it, you would have a hard time coming up with a better melting pot for new viruses than wet markets. Species that do not often coexist in the wild are crammed together, sometimes dead, sometimes alive—and sometimes, as may have happened in late 2019, “you have a bird pooping on a turtle that poops on a civet.” On the other hand, it is unfair because some of the earliest known cases weren’t linked to the wet market—this was simply the place where the first outbreak of the disease became too obvious to ignore, even if it wasn’t immediately possible to establish human-to-human transmission and Chinese authorities were still entertaining the possibility that it was just a nasty outbreak of food poisoning.

In any case, the Chinese government has since cracked down on wet markets, and announced its intention to enforce at least a nominal ban. It remains to be seen whether this will stick, since a similar ban was attempted after SARS. The pressure this time, however, is considerably greater given the global havoc wrought by this disease. But the source of this pandemic doesn’t matter much. Imagine for a moment that you managed, after a good scare and at substantial economic cost, to extinguish a fire in your house. If you want to prevent this from happening again, it would be reasonable to reduce the presence of fire hazards as you fix your house, perhaps by changing some materials in your roof, installing safer kitchen appliances, buying a smoke alarm, and taking greater care with cigarettes. If you eventually discover that the fire was in fact started by an overloaded plug socket, that doesn’t reduce the value of all the other reforms.

One of our most prominent fire hazards is industrial farming. There are various grounds for opposing this practice, including the animal suffering involved, the contribution to greenhouse gas emissions, and the contribution of antibiotics used by farmers to the emergence of treatment-resistant bacteria. More directly, though, it accelerates the emergence of new diseases from livestock, because hygiene is in some cases not much better than that found in the deplored seafood markets of Wuhan. Swine flu is one North American example, transmissible enough to spread far and wide, but considerably less lethal than the common influenza. Avian flu is another Chinese example, highly lethal but with very limited contagion. There is no evidence this was anything other than pure luck; a pathogen similar to SARS-CoV-2 or worse could well arise from industrial farms sooner than later.

Is this whataboutism intended to take the pressure off China? Not at all. Many of the issues with antibiotic use or related pollution in the US and EU are at least as bad, if not worse, in mainland China. However, where we may choose to diverge is the action taken: We should not need to wait for something much worse than the flu or even SARS-CoV-2 to arise before we reform the industrial farming system.

Habitat loss

One may wonder why a topic that usually only concerns environmentalists in sandals is being brought up in this context. But anyone skeptical of the importance of habitat loss need only consult some basic ecology and evolutionary biology. Most diseases that originate in animals jump to humans from mammals. Domesticated animals enjoy close contact with humans in large numbers but wild animals have also been sources of zoonosis, most notably HIV, bat coronaviruses, and ebola. (The jury is still out on whether or not bats are over-represented when it comes to giving us new diseases.)

From an ecological point of view, consider the consequences of deforestation. A virgin forest is not usually destroyed overnight, but cut down so that only smaller “islands” of vegetation remain, often with people living between them. The surface area exposed to people has now increased, and with it the potential contacts that may result in pathogen transmission. That this idea is derived from simple geometry doesn’t mean it is idle speculation. In the case of henipavirus, for example, we find more serology positives in people living around recently deforested area than among those living closer to intact woods. Increased contact with wildlife is the most common transmission mechanism, and it need not be direct: in Malaysia it appears to have occurred through the expansion of pig farms close to bat-attracting mango plantations, while for Mycobacterium ulcerus it seems that the relevant human action was wiping out the predators of the bacterium host. A reckless radical might consider cutting everything down, but aside from the other reasons we might want to keep some forest cover, this appears to make epidemics less likely but worse when they do occur. Once a spillover event linked to habit destruction takes place, contagion may then be aided by climate change which increases the abundance and proliferation of disease vectors like insects.

Evolutionary biology, meanwhile, tells us that biodiversity decline among host animals makes them more vulnerable to disease and helps a larger fraction of their population to become carriers. This is bad news for humans. Examples of the second consequence are legion; high biodiversity among insects bearing diseases such as the West Nile virus or Lyme disease is known to protect humans living close to them. After its arrival with the Columbian exchange, the virus that causes yellow fever established itself in New World monkeys; current deforestation has fragmented their populations to the point that it is believed they have lost their natural herd immunity and have become risky vectors once again for the human population. In Espírito Santo, Brazil, this was noticed soon enough for a timely public health response, but we cannot count on that to save us every time. As with wet markets, a hardline stance against wildlife trade is probably a crucial goal, and one that is already desirable for other reasons.

Protecting natural environments and mitigating the harms of climate change is already a laudable objective. People sometimes wonder if the efforts are worth it, or how it affects them personally if some remote corner of Africa or South America remains green. Whether we like it or not, we live in a very connected world, and emerging pathogens are a reminder that environmental causes all over the world matter to everyone, and in ways more immediate and fatal than gradually rising sea levels.

Experiments in high biosecurity laboratories

British prime ministerial aide Dominic Cummings wrote a useful primer on the issue of biosecurity laboratories in March 2019, reassuringly titled: “The most secure bio-labs routinely make errors that could cause a global pandemic & are about to re-start experiments on pathogens engineered to make them mammalian-airborne-transmissible.” Sounds scary? Well, some authors of more technical literature go even further. One simulation paper even attributes the solution to Fermi’s paradox to biotechnology, arguing that it uniquely empowers the Average Joe, or a team of them, to bring forth an extinction-level or at least civilization-threatening catastrophe. In other words, the reason we have not met ET is because ET has wiped himself out with an engineered virus.

But we don’t need to engage in this kind of lurid speculation. As Cummings’s post points out, historical examples abound. SARS and ebola have escaped biosecurity containment before. It only takes one lapse for a highly lethal, highly transmissible pathogen to leak and for global disaster to follow. Both the US and Russia hold batches of smallpox, and if an accidental outbreak were to occur it is increasingly likely to encounter an immunologically naïve population as mass vaccination campaigns are discontinued.

And it is not only the highest security biolabs that present a risk. Biological laboratories can be classified anywhere between BSL-1, which work with agents known not to cause disease, up to BSL-4, where the lab looks like a bunker within a bunker. International guidelines consider any non-SARS and non-MERS coronavirus, even an unknown one, deserving of only BSL-2 protocols. Having worked in BSL-2 laboratories myself, I find this outrageous because this means technicians are not wearing proper protection from aerosolized transmission.

Relatively simple precautions like wearing double gloves with no unprotected space in your sleeve, face coverings, and decontamination equipment are enough to block airborne transmission, and these measures are appropriate, not only when technicians don’t know what they’re working with, but also when they are aware that some of its close relatives are really dangerous. It is by no means proven but remains possible that the “patient zero” of SARS-CoV-2 was a research assistant studying the natural pool of viral load in local bats at Wuhan: Something like this virus could probably infect a worker even if she was abiding by the protective measures required under those guidelines.

It is therefore necessary to revise our judgment about the convenience of some experiments, and to secure maximum biosecurity laboratories against human error even more than before. We must also take advantage of this opportunity to revise all our standards for bacterial and virological research, and substantially increase the security requirements that we find too lax. This might result in fewer places in the world where certain research can be carried out. This is unfortunate, but the stakes are high enough to justify this.

Healthcare preparedness, funding, and regulation

If we cannot avert pandemic risk completely, we can surely mitigate the damage future outbreaks will cause, and for a fraction of what our manifest unpreparedness has cost us this time. There is plenty of scientific literature on this, most of which was prepared for something like the second coming of the Spanish flu. It recommended stocking up a surplus of masks and similar protective equipment for healthcare workers, as well as ventilators and similar supplies for the patients of a sudden and novel outbreak. Depending on which party is ruling a given country, and which party is associated with healthcare spending cuts, these issues have been used as either exculpatory for the loss of life during the SARS-CoV-2 crisis or as a political cudgel with which to beat the current government. This politicization should not distract us from the fact that we were warned, and that even this low cost of risk prevention measure was neglected.

Aside from local production and stockpiles of relevant material (with assistance for smaller or poorer countries where this would be more difficult), how we manage and invest in hospital organization could make the difference. In one sense, the German response has been a failure compared to countries that prevented outbreaks more completely like Mongolia or Vietnam. But in another sense, Germany’s handling of its outbreak compares favorably with the experience of countries that were hit even harder. The German hospital system has previously been called inefficient for having too many hospitals and too many beds, but it is their high per capita ICU capacity and the promptness of their test and trace response to which many observers now attribute their relatively low case fatality rate and better containment of the disease. The United States is also doing better than might have been expected on the basis of its notoriously unequal healthcare system, due to the high ICU capacity created by that very system.

Likewise, there is no way of avoiding the need for proper funding and regulation. Although scientists begging for increased funding resemble bird hatchlings demanding the worm, in this instance it is entirely appropriate. I cannot do no better than direct sympathetic policymakers (or those able to influence them) back to Toby Ord’s section on the topic in The Precipice. Some of his proposals are as simple as increasing funding for the Biological Weapons Convention from $1.4 million up to $80 million, a figure chosen to match the funding of the Chemical Weapons Convention. Ord also recommends increased transparency regarding mistakes made in BSL-3 and BSL-4 labs, and suggests developing appropriately paranoid protocols to protect information that could be used for bioterrorism. Other proposals are bound to be controversial in the current news climate, such as empowering the WHO’s disease response, diagnosis, and surveillance capacities. This job might be better performed by someone else, but we cannot escape the fact that someone will have to do it. Whatever one thinks of the organization that coordinated the eradication of smallpox, someone must to able to orchestrate international cooperation for purposes that matter to us all, whether it’s the WHO or some other body.

As for the surveillance projects, since we all now inhabit a cyberpunk world, it is perhaps inevitable that one of these is called the Sentinel Project. It aims for low cost preparedness and swift emergency response that it is hoped will prevent future pandemics. We already have promising methods to predict the pandemic potential of pathogens, and perhaps one day genetic data will be used to quickly develop treatments when a new outbreak occurs. Others prefer to focus on populations where new outbreaks might emerge, surveying persons instead of viruses, including with immunological surveys. A recent article in National Geographic contains information about how surveys for emerging diseases would work, including the discovery of what might be another ebola outbreak/epidemic in the making. Following the cost-benefit analysis and the fire hazard analogy with which we began, it is reasonable to invest enough resources that we do not have to choose. This isn’t limited to teams that work on research, however. Some moves should simply require stricter enforcement of what many of the relevant companies do on their own. For example, ordering a smallpox sequence is currently closer to ordering a present for a friend on Amazon than to the sci-fi process many probably imagine it would require. Ending this would be as easy as enforcing the automatic screening that 80 percent of DNA synthesis companies already do.

It might sound like the height of bad taste to say this at a time when more than half a million lives have been lost to COVID-19—a death toll that is expected to increase—but this disease could end up being remembered as a relatively mild wake-up call compared to the threats to come. The novelty of this disease can make it seem worse than smallpox, the Spanish flu, or the Black Death, but each of those diseases cut an unimaginable swathe through the societies they struck. Indeed, some senior policymakers and commentators have until now been focused on preparing for bioterrorist threats; the nightmare scenario has hitherto been the creation of a strain of avian flu, with a mortality rate of 30 percent aided by airborne transmission. So yes, compared to the repertoire of possible pandemics, what we are living through now amounts to a stern warning. We can take this warning on board, and focus the necessary resources and research on reducing the risk of these threats, or we can rue this missed opportunity as we pick through the body bags and mass graves of a greater plague yet to come.

 

Javier Arcos Hódar is a researcher in the Alberto Sols Biomedical Research Institute, Madrid.

Featured image Anton Croos, Art of Photography.

Comments

  1. “Sounds scary? Well, some authors of more technical literature go even further.”

    No doubt they do. But is it science, or precauction, or fear-mongering? The real danger of some unspecified “greater plague” is that we’re expected to live under a shadow forever.

  2. I notice that we can’t do all of these at once. Reducing industrial farming while maintaining a sufficient food supply means that we would have to spread out our area of production, greatly reducing habitats and increasing the amount of land use by agrigulture. This would run counter to the suggestion that we reduce habitat destruction. Given that the author hasn’t provided us with any kind of hierarchy for effectiveness or preference, I am left to wonder which he would choose.

  3. A really interesting and well informed article. As the warnings of recent years had obviously not been sufficient to encourage politicians and the public in most countries (with the exception of a few in South East Asia) to take sensible precautions, the COVID-19 pandemic could be seen as a warning shot.

    Or maybe not. Unfortunately, as Nassim Taleb rightly described, if a politician prevents a disaster from happening by taking sensible precautions in advance, nobody will thank them because nobody will even notice that a disaster has been prevented.

    In order to gain fame and glory, it is therefore better to concentrate on more rewarding topics, wait for the danger to occur eventually and then fight it successfully in front of everyone. This may be much more expensive and risky, but it’s certainly the better way to become famous and celebrated.

    It’s unfortunate, but difficult to change, because that’s the way the majority of people are.

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