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The Herd Immunity Taboo

Purity and danger: Why some are strangely comforted by lockdowns, fearful of herd immunity, and quick to punish anyone who questions the stark choice between them

Norman Doidge
May 20, 2020
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Herds of bison near Lake Jessie, North Dakota, ca. 1850MPI/Getty Images

As I explained in an earlier journal entry, once a pandemic breaks out, our evolutionary-based behavioral immune system (BIS)—that complex of instincts, attitudes, and behaviors that developed to protect us from potentially infectious people—switches on, and we become predisposed to feel afraid of and disgusted by anyone that might be infected or spread infection, and give them wide berth. For good reason, the BIS tends to fire “false positives” and err on the side that says an infection might be there, even when it isn’t. Its job is not to fight a well-established infection with obvious, easy-to-recognize symptoms—that is the job of the regular immune system. The BIS’s job is to detect potential infections—that may be developing, so the slightest cough or sneeze, or sniffle, or the wrong travel history in a guest, is enough to set it off so we don’t get sick in the first place. It can even turn on with the news that an infected person has arrived in your neighborhood.

Once on, the BIS is not easily switched off, again because it is so prone to fire false positives. Now that it is on, even the thought of leaving lockdown at some point is particularly terrifying for people with a perceived sense of vulnerability to infection. All else being equal, they feel “safest” in lockdown. They can only imagine leaving lockdown voluntarily when there is some kind of scientific, “all-clear sign” that says the virus is nonexistent, which then deactivates their BIS. But the idea of leaving before that seems out of the question.

The behavioral immune systems of much of the U.S. mainstream media is on fire right now and many outlets have generally been passionate opponents of lifting the lockdown. Part of that is because President Donald Trump has come out for easing it, sooner than later, so his many opponents are, as to be expected, against. In the United States, where the pandemic is hyperpoliticized, lockdown’s logic is now taken as an article of faith by many. Questioning the long-term efficacy of lockdowns is seen as dangerous. So is discussing “herd immunity.” Herd immunity is the natural immunity that builds up in a population when people (often younger and healthier members) are exposed to the virus, get ill, and then recover in large enough numbers to ultimately block the spread and shield the more vulnerable from being exposed. At the moment, even discussing whether herd immunity might play a role in emerging from lockdowns is depicted as a heartless, foolish right-wing policy (even though the leading proponent of herd immunity has been the left-wing socialist government of Sweden). But there’s more to it. The U.S. media are centered in New York City, the world’s epicenter at the moment, and members often assume the New York experience is universal, and New York’s experience has been horrible. As members of the media, they are exempt from lockdown’s most stringent isolation restrictions, and are still working, so it doesn’t seem quite so bad to them.

And of course, lockdown is great drama, as would be a new vaccine, but the possibility of a slow incremental improvement, a slow building up of community-immunity to shield the vulnerable, is… boring.

Once the behavioral immune system is firing in a population, the very thought of an alternative to it that involves people getting infected, becomes taboo. Whoever argues for it risks being treated like an infectious agent, and being ostracized. (Please don’t ostracize me, dear reader, for saying so! I’m not here making an argument for, or against. I’m trying to describe how, once we accept the logic of lockdown, our thoughts about how to get out of it become paralyzed by our protective instincts.)

It’s fascinating that even trying to think through the idea of a herd immunity strategy can arouse terror and rage in us—even though, we might be well aware, in the very same instant, that lockdown is not a sustainable strategy because of the total harm it does, not only to the economy, but to health, mortality (increases in untreated cancers, missed cancer diagnoses, strokes, heart attacks, suicide, appendicitis attacks, drug addiction, murder secondary to domestic abuse, etc.). Those “non-corona” deaths or morbidities—not listed on the Johns Hopkins COVID site—must obviously be taken into account before proclaiming that the lockdown approach is more humane than the herd immunity approach.

The Shifting Policies of the Pillars of Science

Lockdowns and herd immunity might reasonably both be seen as partial, interconnected strategies and yet these dynamic experiments in public health policy are treated as mutually exclusive, all-or-nothing articles of faith. How has this come to be? Most people had likely never heard the term “herd immunity” this time last year. To understand what has so galvanized the public debate about these concepts, we can begin by looking to the pillars of scientific expertise guiding pandemic policy. Global authorities like the World Health Organization.

The World Health Organization is “guided by the best available science, evidence and technical expertise,” according to its own “values statement.” So guided, it guides the world. What does such guidance look like?

On Jan. 29, Dr. Michael Ryan, executive director of the World Health Organization Emergencies Programme, praised and endorsed the China-style lockdown, and its rigorous measures, because they were proving so effective. Ryan said, “China is doing the right things, and China is responding in a massive way…” Videos released from China showed that when Xi’s government said “lock down” they meant it not metaphorically, but “scientifically.” They literally locked people into their homes by welding their doors to their apartment buildings shut—not making clear how they were supposed to get food. Ryan added, “We’ve seen no obvious lack of transparency,” perhaps because people who reported on such details often disappeared into thin air. By Jan. 30, WHO officials were not only arguing that the Chinese government’s approach was right for China. It was—as WHO head Tedros Adhanom had said—“setting a new standard in outbreak,” for other countries.

Then, on March 30, Dr. Ryan suggested that because many people infect their families in the kind of lockdowns the WHO had just commended, “we need to go and look in families to find those people who may be sick and remove them and isolate them in a safe and dignified manner. …” This was confusing, because he was promoting this scientific policy at the very moment when other equally scientific public health officials, such as those in the CDC, were recommending the opposite policy: People with COVID should stay at home, with their families, but in a separate room if possible, and if not, wear a face covering, unless they had trouble breathing. Then, they could go to the hospital, but otherwise, best not to overwhelm the emergency rooms.

Meanwhile, some became alarmed that at a time when governments have been given unprecedented powers, a WHO endorsement of authorities throughout the world “to go and look in … and remove” would mean that armed men in hazmat suits, would come, bang down the door, then drag people kicking screaming from their homes in a “safe and dignified manner.” Multiple videos and reports showed that that was exactly what was happening in China.

No matter; on April 29, suddenly Dr. Ryan had had enough of the authoritarian/totalitarian-style lockdown model, and he said, “If we are to reach a ‘new normal’ in many ways Sweden represents a future model. … What it has done differently [italics mine] is that it really, really has trusted its own communities to implement that physical distancing.”

“Shield or herd immunity, when practiced in a country like Sweden, is not about ‘the survival of the fittest’ or ‘culling of the herd.’” Stockholm, April 22, 2020.
“Shield or herd immunity, when practiced in a country like Sweden, is not about ‘the survival of the fittest’ or ‘culling of the herd.’” Stockholm, April 22, 2020. JONATHAN NACKSTRAND/AFP via Getty Images

Not only did the Swedes avoid authoritarianism and trust individuals to voluntarily implement the measures, they avoided lockdown from the very beginning of the pandemic. They kept restaurants and most businesses, schools, and gyms open, and have observed social distancing. They also requested that people 70 years and over, and the vulnerable, shelter in place. Realizing it was mostly the elderly and the sick who died in Italy and Wuhan, they hoped those who were younger and healthier and who were out mingling, would be able to handle the virus if they got it, and have infections that were either completely asymptomatic, or mild, or at least not requiring hospitalization. In the process, they would, it was hoped, develop an immune response and antibodies against it. The Swedes turned out to be correct that the majority of infections were mild enough not to require hospitalization.

They knew that in the early days of their program, their case rates of COVID sickness, and death, might well be greater than in other similar countries. They took care that their hospitals did not get overwhelmed. (They weren’t.) They hoped that over the course of a year or so, they would experience no more, and possibly even fewer deaths, than in similar countries, because so many in the Swedish “herd,” or population, would have developed resistance to the virus. By the end of April, the country’s lead epidemiologist, Anders Tegnell, estimated that 25% of people in Stockholm had been exposed to the virus and were already probably immune, and he reported a survey of one of the city’s hospitals which showed 27% of the staff was now immune. He hoped Stockholm would reach herd immunity in a matter of weeks. Epidemiologists guess that 60%-80% of a population would be needed to have been exposed (and recover) for herd immunity to occur.

Herd immunity, when it develops, either naturally or with a vaccine (which imitates natural herd immunity), blunts a virus’s effect in two ways. First, the virus is beaten back in that infected person’s body, so they are helped. Second, that person, once they are recovered, becomes much less likely to spread it to others. The recovered, now immune person ceases to be a “vector” to spread the virus further. That is bad news for the virus. These people ultimately form a “shield” that protects the vulnerable. Some scientists call this “shield immunity”—perhaps a better term—and spend their days working out the math, to determine how many people are needed to shield the vulnerable, and the society as a whole, and how to use antibody tests to further this strategy.

Shield or herd immunity, when practiced in a country like Sweden, is not about “the survival of the fittest” or “culling of the herd,” because while it is taking hold, an effort must be made to isolate and protect the vulnerable, because before those robust young people have developed antibodies, they might well infect the vulnerable. But truth be told, few countries, Sweden included, have done well protecting the elderly.

The goal of the Swedish model was also to keep their economy from collapsing (hard to do when the rest of Europe is in lockdown), avoid mass poverty, and the sickness and death that isolation produce. This was based on their assessment that while it is easy to say, “we will stay indoors until the vaccine comes” in fact, there is no certainty a safe and effective vaccine will arrive in sufficient time. It is also questionable how long populations can tolerate full lockdown psychologically without erupting—as was seen this past weekend, in many countries which did a slight easing of their lockdowns. Hundreds of thousands of citizens, many of them young and not perceiving themselves as vulnerable to infection, having been given their first taste of freedom, and throwing all caution to the winds, in a joyful spring revolt, ceased social distancing in public, as though they felt, having survived the lockdown, they had survived the virus too.

It is as though the Swedes had either reasoned, or by accident discovered, that just as populations must be trained to relinquish freedoms to go into lockdown, they would have also to be trained, over time, to emerge from them—call it unlockdown training—and how to function as free people, on the outside, in the presence of the virus, and that that might even be a harder task than learning to lockdown, and even harder still to learn after the lockdown, freedom suddenly providing many social temptations to people so pent up with longing; but, the Swedes also saw that living unlockeddown would be the more essential task for long-term survival. And so, they went, more directly, to the more difficult task.

The Swedish strategy argues that mass lockdown quickly becomes too blunt a measure, filled with waste, and unneeded negative consequences, and that, given human nature and biology, it can’t ultimately be sustained. It argues for a far more “strategic” or “surgical” lockdown of the most vulnerable—the elderly, many of whom have diseases that are risk factors for COVID-19 and who, in many countries, make up well over 80% of all the deaths. Protecting them better might involve paying staff to work in just one nursing home, so they don’t introduce the virus from one to another, expanding quarantine space in nursing homes, and concentrating testing there, while the rest of the population goes out and develops herd immunity, at which point the surgical lockdown would be lifted.

At first the U.K. flirted with a herd immunity strategy—though the government now denies it, probably for fear of being sued for not declaring that the only policy the U.K. would ever conceivably pursue would be one that would not countenance a single citizen succumbing to the virus—something utterly beyond its grasp, of course. Scientists from the Oxford research group, had in fact, developed a model that suggested half of the U.K. population already had been infected, which meant that fewer than 1 in 1,000 of those infected were ill enough to require hospitalization. They also speculated that people had been infected much earlier than had been thought (now known to be true in many countries), and that this probably meant that a protective “herd immunity” was therefore already building in the U.K., and the authors pleaded for the U.K. to do testing to confirm this. However, the lead scientist from the Imperial College, Neil Ferguson—whose numbers were hugely at odds with those of the Oxford group—said his model showed that 500,000 people would die in the U.K. (and 2.2 million in the U.S.). Ferguson ultimately persuaded/terrified the politicians in both countries into a lockdown strategy. The hope was to make sure the NHS was not overloaded with cases. The herd immunity approach seemed done for.

Until the WHO’s Dr. Ryan made his about-face. He papered over this turning from the Chinese to the Swedish model by implying it was a logical, scientific evolution, appropriate for this next stage of the pandemic. But, in fact, Sweden had been using nonlockdown for every stage of the pandemic, and so, the new position contradicted his early praise of China for doing all “the right things.” This change of heart is to my mind the most stunning “scientific” reversal of the pandemic, and it shows that the logic of involuntary lockdown is now being questioned by the very WHO officials who initially endorsed rolling it out across the globe.

Lockdown treats us as equals: it declares we are all vulnerable, all working for each other, against the deadly foe. Herd immunity divides us, because it argues that this deadliness does not apply to all equally, as many of the young already sense.

Lockdown is a total suppression strategy designed to prevent people from spreading the virus beyond their immediate family if they live with them or their roommates. Initially, when we knew nothing of the virus, there was a strong case to be made for lockdown as a temporary measure—to be in place for a number of weeks or a few months, which is how it was sold—to buy time to learn about the virus, the illness, and how to treat it. At the time, we had good reason to believe health care systems everywhere would be overwhelmed, because they were in the first two viral centers, Wuhan and northern Italy, where care was denied to people over 60 who were dying, for instance. The early WHO case fatality statistics (which were based on testing of the sickest patients, who came to hospital, and so presented a worst case scenario in terms of the predicted death rate), and the British Imperial Report (which turned out to be deeply flawed), both suggested that all countries would face a situation in which health care systems would be overwhelmed with patients, as were Italy and Wuhan.

Much was learned during the lockdown period. We learned that patients placed on ventilators had 80% death rates, but then, also, more about how to keep up to two-thirds of people off them, and how to better treat them earlier with oxygen, a huge breakthrough that saved many lives. We saw that in most jurisdictions in the democracies, hospitals were not overwhelmed. We developed our first effective tests for antibodies, and for the virus. And learned that most cases are mild enough not to need hospitalization, and that this suggested that people might indeed be developing resistance.

One of the most important things we learned is that 99% of people who get COVID-19 develop antibodies to the coronavirus (even that was in doubt in the early days). This was shown in a large major study, by Ania Wajnberg, and multiple colleagues from the Icahn School of Medicine at Mount Sinai Hospital New York, which released preliminary results on May 5. This study used a new antibody test, developed by Florian Kramer, that has a rate of only 1% false positives (meaning when it says antibodies are present, it isn’t exaggerating the amount by more than 1%). The study was of people who had had COVID-19, survived it, and who were now offering their antibodies for doctors to give to others who might get a serious form of the illness, in the hope that these antibodies might save their lives. Call them antibody donors.

The next steps to sealing the argument for herd immunity scientifically is to see if COVID-19 antibodies confer immunity over time—which is not far-fetched, because, after all that is what antibodies generally evolved to do, even if they don’t always succeed. We also want to see if those with asymptomatic illness also develop full immunity, and learn how long they remain infectious. Then we must see how long immunity lasts—something which may depend on the virus’s own permutations. Hoping these antibodies will confer immunity, and that it will last, are reasonable hopes, but hopes nonetheless, as lockdown proponents can point out, saying that until all of these matters are scientifically certain, anyone who argues for easing the lockdown restrictions now is simply “in denial.”

Danger Through Purity

But the lockdown logic has its weak points too, one in particular that wreaks havoc with our psychology—and here I don’t mean the well-known despair caused by isolation, which is especially deadly for those who live alone or with those whom they can’t stand, or the despair caused by total economic devastation.

Lockdown has always posed a serious problem that even its exponents, who are skeptical of herd immunity, can’t deny. After the virus has initially spread through a country, the more the lockdown succeeds—and keeps indoor bodies virgin pure and free of the virus—the more likely it is, when the lockdown is lifted, that the virus will rage and kill again, in second, third and fourth waves—as long it has not been completely obliterated from planet Earth. It’s inevitable by lockdown’s own logic. The very purity of the lockdown guarantees danger going forward, and undermines hope for anyone who takes the logic seriously. The pain is deepened and prolonged; with each passing day, the population exhausted, depleted, and of course financially ruined, until, ultimately, it becomes rebellious, which happens recurrently in the history of plagues.

Lockdown also bequeaths us a map, in which my little home, my apartment, my room, the world inside is good and safe; but the outside, is nothing but dangerous. It begins by physically enclosing us, but ends by mentally enclosing us. We may not be paranoid (because there truly is a virus out there), but we nonetheless start living as paranoids do. Lockdown forecloses unlockdown.

That is one of the reasons why what began as a “temporary lockdown” to flatten the curve, in order not to overwhelm our hospitals—a dire outcome that has not materialized in most places—has turned into an extended lockdown in many places. Psychologically, then, the premises behind lockdown demand that we think the outside world as too dangerous for us to handle. Some of us can manage this for a while; others can’t.

Public health officials don’t deny this is true; they just promise to solve the problem with “the vaccine.”

Vaccine supporters don’t just argue a vaccine will save us. They say it is the only thing that can restore our lives as normal, congregating social animals, because they believe long-term lockdown, which they increasingly advocate, never will. All plagues put populations through exhausting manic-depressive cycles of hope and despair, and as intelligent people have watched the WHO and public health officials flip flop on multiple issues, doubt accumulates about our scientific grasp. The “vaccine” seems the one thing we can resort to, to restore our wavering certainty. As Bill Gates has said,

The ultimate solution, the only thing [italics mine] that really lets us go back completely to normal and feel good about sitting in a stadium with lots of other people, is to create a vaccine.

But even Gates and Anthony Fauci concede 18 months is required to get one, and that that would involve skipping normal safety testing—which produces more uncertainty. Safety testing occurs because vaccines, at times, have killed people, especially in mass vaccination programs. In 1976, people developed neurological disease from the rushed swine flu vaccine, so the entire program had to be shut down. The first corona vaccines, for cats, actually made them more prone to getting severe disease and succumbing to it, and other animal studies of the vaccine showed it triggered dangerous inflammatory reactions. There is a reason that responsible health professionals want a vaccine that is both effective and safe. (And safe means not just that the person is well for a few weeks after they get their shot, but that they don’t develop long-term side effects.)

But if it is reasonable to hope for a vaccine not yet invented, or proven safe, to save us, why do we not hear scientists speak more about herd or shield immunity, and how it might be managed, or manipulated in some way, to protect us in the meantime?

That’s because the herd immunity approach has several big disadvantages, even if all its premises are true. First, it might cause more deaths up front, and second, it freaks people out.

YouTube Becomes YouTaboo: Internet Police Force of the Behavioral Immune System

It especially freaks out populations that have just been trained to enter, and remain in, lockdown with a combination of data, scare tactics, 24/7 death charts, and even talking police drones (such as appeared in the skies of Elizabeth, New Jersey, recently, scolding people who were not social distancing with, “You are not immune to the virus”).

As we saw in Britain, democratic politicians are terrified to discuss herd immunity openly, because to endorse it is to concede something unpalatable in a modern democracy: that the government’s policy is actually to permit some people to get ill. And of course, those who get sick and don’t recover will be used to bring that government down.

Lockdown can at least justify itself with the promise that our science will create a vaccine that will reopen the door to normalcy, and it supplies the reassuring fantasy that we are in control after all.

Herd immunity, as policy, is a way of working with nature that begins by accepting that we do not have as much control over nature as we wish, and that the vaccine may not arrive in time. Lockdown treats us as equals: It declares we are all vulnerable, all working for each other, against the deadly foe. Herd immunity divides us, because it argues that this deadliness does not apply to all equally, as many of the young already sense.

It is not only politicians that are hesitant to endorse it. Scientists and clinicians who believe that it is essential we take shield immunity into our arsenal to defeat this virus are have been censored. In cases, their reputations have been savaged, and this caused other scientific critics of perpetual lockdown to back off.

Not everyone speaking of herd immunity has been blocked in the media. Ivy League credentials sometimes help. The thoughtful public health physician David L. Katz, founder of Yale University’s Yale-Griffin Prevention Research Center has managed to make the argument for herd immunity in The New York Times.

But many can’t get the case heard. At a time when people are spending more time online than ever before, and when YouTube is the biggest online platform, it is hugely significant that Google, through YouTube, had started censoring scientists and epidemiologists that have questioned the lockdown. YouTube CEO Susan Wojciki explained to CNN’s Reliable Sources host Brian Stelter that “Anything that goes against WHO recommendations would be a violation of our policy and so remove is another really important part of our policy.”

Note, Wojciki said, “Anything.”

Thus spake YouTaboo, even though the WHO is all over the map on its recommendations, and thus itself contradicts WHO policies one day to the next. YouTube proceeded to cut off critics of the lockdown, eliminating videos by experienced epidemiologists and physicians (more below). It’s bizarre that an administrator would believe it would be helpful to censor science, especially at a moment when science is in such obvious flux. But then, taboos are usually bizarre. So why do we create them?

Purity and Danger

In this context, I like the approach of the English social anthropologist Mary Douglas, spelled out in her book Purity and Danger, on the ideas of pollution and contagion in cultures ancient and modern, primitive and industrialized. A taboo, Douglas writes, is:

A spontaneous device for protecting the distinctive categories of the universe. Taboo protects the local consensus on how the world is organized. It shores up wavering certainty. It reduces intellectual and social disorder.

The censorship, at this moment, is shoring up the wavering certainty we feel as we go through another cycle of science says “do this,” and science says, “do that,” as seen with the WHO reversal on herd immunity. We are a science-driven society, and almost all educated people believe in science, and many flatter themselves that they follow it. When we fear we are facing a mortal peril, and our scientists are contradicting themselves, or other scientists, our own identities are threatened, because science is not just a tool for us, but rather central to our identity. Our faith in it, its promise that we can control fate, is what supposedly distinguishes us from our helpless predecessors whose attitude toward plagues was generally resignation. And suddenly, with its many about-faces, science is generating not certainty, but uncertainty, and perhaps we momentarily feel no better off than they, the primitive ancestors we are supposed to have transcended; an uncanny feeling.

Douglas goes on to ask, “We may well ask why is it necessary to protect the primary distinctions of the universe, and why are taboos so bizarre?”

When our distinctions can’t be held, ambiguity arises. Ambiguity in our core categories (including particularly those that help define our identities) becomes extremely threatening, and dangerous. In response to this danger that arises when fundamental distinctions or categories are breaking down—we reinstitute them with a focus “purity” to protect ourselves from the ambiguity. And we enforce this purity with taboos, and even micro-taboos.

What is especially hard to accept at the moment, is that science has not yet answered all our questions so that we can know with a comforting level of certainty, what policy is best. We must live, for the moment, with some ambiguity. Those who can’t handle this ambiguity are promoting false certainty, the product of some fictional settled science, and anyone who deviates from that must become YouTaboo, unclean, impure.

Douglas quoted an old English aphorism, and made it central to her work: “dirt is simply matter out of place.” A leaf on your lawn is a delight, on your carpet, it is dirt. The plastic top of your take-out coffee cup, on the kitchen table is unnoticed, but on the floor, it is “garbage.” Food on your plate is wholesome, on your necktie, filth. The concept of dirt, for Douglas, always implies an ordered system of where things belong. Dirt is a kind of “compendium category” for anything which might “blur, smudge, contradict, or otherwise confuse accepted classifications. The underlying feeling is that a system of values which is habitually expressed in a given arrangement of things has been violated.”

People can become dirt, too, and be defiled, if they happen to say the wrong thing at the wrong time, or in the wrong place.

Before the WHO did its reversal and spoke out for the Swedish model, several American epidemiologists had dared to. One of them is the epidemiologist Knut Wittkowski, Ph.D., who spent 20 years as head of the Department of Biostatistics, Epidemiology, and Research Design at The Rockefeller University, New York. He had been an advocate of herd immunity, critical of indiscriminate lockdowns, and even of the language used to enforce them, including the constant emphasis that corona is “novel,” because it stirs up so much panic (which shuts down reason). As he points out, “Every virus that spreads is novel. If it were not novel it would not spread because then we would have antibodies against it. Having a novel virus is not novel.” Each year, for instance, there are novel influenza viruses, which is why new vaccines are made. He argued that if this virus were to behave as most known respiratory viruses, those who survive it would be resistant. His position was that, for now, only the elderly and vulnerable should be in “lockdown” or quarantined. He also questioned WHO case fatality rates. For proposing something much like the Swedish model a few too many weeks before the WHO, Wittkowski was attacked. He spoke, alas, at the wrong time. He was falsely accused of claiming he was a “professor” at Rockefeller (he clearly did not). One of his key videos was removed from YouTube. So have the videos of physicians who similarly used statistics and their medical experience to argue for moving toward more of a Swedish model (once they went viral, and had an influence).

This is why a plague is called a plague: It creates a situation in which most every option is bad, and sorting out which is least bad plagues and torments any honest mind. But the solution is not to make that act of thinking taboo.

Stanford’s highly esteemed John Ioannidis, MD, an Athens-raised American epidemiologist, is one of the most thoughtful physicians in the world and one of the top 100 most cited scientific researchers alive, with more than 1,000 publications. He is famous for his careful methodological work pointing out that many medical studies in the mainstream journals could not be replicated and were hampered by biases. Ioannidis was also one of the first to question the accuracy of WHO case fatality rates, and pointed out the lockdown policy was not based on evidence since we hadn’t gathered enough of it yet, but rather was motivated by “gut feelings.” He didn’t say the lockdown was wrong (he was himself sheltering in), just that it wasn’t based on science, or knowledge of whether our actions would lead to more harm than good.

Around this time the most comprehensive testing undertaken in New York to determine the infection rate showed that 21% of people in New York City had COVID antibodies as of mid-April (and presumably many more now). This suggested that many more New Yorkers had been exposed to the virus than previously believed, and that the death rate from exposure was much lower than had been believed. These death rates were much more in line with the rates Ioannidis was finding in other data sets. Since the overwhelming majority of these New Yorkers who showed antibodies seemed healthy, the testing appeared to suggest they indeed had resistance, and that herd immunity was probably building. He reported on similar suggestions emerging from the cramped Diamond Princess Cruise, and from the fact that most young people seemed spared, and from findings in Iceland, which tested 5% of its population. All this testing suggested that there were more mild cases than the WHO data suggested, and that herd immunity might be building, though he was at pains to say we still needed more data.

Ioannidis then, working with other scientists, did their own antibody study in California, and the group claimed their study also showed that the WHO death rates were far off, at least for California, by an order of magnitude, and that the numbers used to justify locking down were very likely not relevant in many places. He used one of the existing, imperfect antibody tests, and, as is routine during the COVID era, put the study online before peer review. There were some thoughtful reviews in which authors suggested the study had some errors from a statistical point of view, given the accuracy issues with the antibody study used. Ioannidis is as capable of correcting errors as anyone, if they are pointed out, and already did publish one correction.

It is what happened next that speaks to the frenzied forces purity and danger can unleash. Ioannidis was greeted with intense anger, pilloried nonstop, caricatured as implying COVID-19 is not severe (he actually said it was “the major threat the world is facing”) and generally demonized. He was morally vilified—not told, “I think you made a mistake,” but “how dare you betray everything you stood for.” Et tu Brute articles and comments by peers and journalists have appeared on the internet, depicting him as sloppy, skewed, doing horrible science that no one believes, and even being on the take, fixing his results for money. That was a smear (so-called because the idea is to dirty a clean reputation). Fellow scientists treated him as a threat whose errant thinking would erode public confidence in current measures, and criticized him for publishing not in peer review journals but in public (i.e., he was in the wrong place)—not that his critics waited to publish their criticisms of him in peer-review journals.

The point here is not whether Ioannidis was right or wrong. Any attacks in such a situation can always be justified by the charge, “if he gets this wrong, people will die.” It’s without doubt true that if the advocates of herd immunity are wrong people will die needlessly. But it is also true, without doubt, that if advocates of lockdown are wrong, people will die needlessly. This is why a plague is called a plague: It creates a situation in which most every option is bad, and sorting out which is least bad plagues and torments any honest mind. But the solution is not to make that act of thinking taboo.

Ioannides had crossed the behavioral immune system. He became taboo in part because he was one of the first epidemiologists from a prestigious university—a member of that club—who broke ranks with leading public health officials and joined the far less popular club that is criticizing the WHO, the pinnacle of global public health cooperation. It isn’t possible to be a member of both clubs at once! That is definitely out of place, impure, and it makes John Ioannides an ambiguous category, neither fish nor fowl, neither a creature of the sea or land.

We, the children of science and medicine, don’t say, “you will be punished by God for being impure,” since we don’t believe in divine punishment, thunderbolts, or even plagues as being provoked by bad morals (or so we say). But we do endlessly threaten ourselves, or each other, that should we think the wrong thoughts, or do the wrong things (such as eat the wrong foods, drink unclean water, use the wrong forms of energy, take the wrong medicine) there will be dire consequences to our health, or that of the planet. Douglas writes, “Grown-up practice uses impaired health as the threat. … Feared contagion extends the danger of a broken taboo to the whole community.”

Taboos, because absurd, always have to be maintained by societal complicity, says Douglas. That’s easy in a dictatorship. In a free society, it is harder, and it necessitates the self-censorship of the media—a role that Google and the Google-owned YouTube have been only too happy to play.

We are fortunate that the WHO, such as it is, doesn’t have the power to enforce a single global policy at this time (though it wishes it had). This power vacuum allows different countries to take different approaches, and the rest of us to see how they do, empirically. The best policy may vary from place to place, culture to culture, genetic group to genetic group, and vary, too, by how unhealthy the existing population is, with respect to the known risk factors. The United States, for instance, already had two prior uncontrolled, noninfectious epidemics, before corona arrived: among the highest rates of diabetes and obesity in the world, both of which are risk factors for COVID, for instance. How would they be best protected if a general lockdown is lifted?

I am aware that to explain how hard it is to think through and discuss policies in a plague, I have brought together two very different concepts: the behavioral immune system, which is an instinctual response designed to protect us from infection, and Mary Douglas’ ideas. Douglas made a point of emphasizing that what one group sees as dangerous, dirty and unclean, doesn’t necessarily map directly onto our biology, or the modern idea of microorganisms—that is only a recent phenomenon. She might not have approved of my linking the biological behavioral immune system so closely with her ideas, because she emphasized the tremendous variation in terms of what was taboo, dangerous, and impure, from one group to the next.

But the behavioral immune system, although it has biological roots, is plastic, and affected by cultural experience. What we react to as potentially infectious, are disgusted by, fear, and avoid, is in part determined by what we are taught, or learn, might make us sick. It would, after all, require a dramatic reversal of categories to go from a lockdown logic, which sees asymptomatic carriers of the virus as potential assassins who might infect us and other vulnerable people, to a herd immunity logic which sees them—ultimately—as potential “shields” who might actually protect the vulnerable. That shift would, for many people, upend their current view of the situation and the world. Should we, at some point, get the magical, “all-clear signal,” either from a vaccine success, or from herd immunity building, the BIS will then, finally, start turning itself off—not all at once but in stages. Then these foolish, self-destructive taboos will be dropped, and replaced by others equally foolish for a different reason.

As for irrelevant me, dear Diary, what do I, at the moment, think is the better course, the promise and the risk of going for herd immunity now, versus the promise and the risk of staying in lockdown until we have more testing done, so as to eliminate more uncertainty? I’m developing a preference, but I won’t share it, even with you, because I’m uncomfortable having noticed that I still fluctuate in my assessment, and that what determines my fluctuation is not my reason, or my limited knowledge, or my restlessness, but rather an inconstant cue, that sometimes turns on, and sometimes quiets, my behavioral immune system’s activation: i.e., my own perceived vulnerability to infection at a given moment. My heart is not yet pure. And that’s not good enough.

Norman Doidge, a contributing writer for Tablet, is a psychiatrist, psychoanalyst, and author of The Brain That Changes Itself and The Brain’s Way of Healing.