The other day, I was perusing the hellsite known as Twitter before it becomes even more of a hellsite after Elon Musk acquires it, when I came across this series of Tweets about a favorite topic of this blog for the last year and a half, the Great Barrington Declaration. I’ll quote the first few, so that you can see why they would have interested me, namely because they are about a study that provides yet more evidence to support what I’ve been arguing about the Great Barrington Declaration ever since it was first published:
Even though I’ve decreased my blogging frequency because my wife and I are fostering puppies again, I knew I had to write about this study. First, however, let’s take a look at the puppies.
Then, let’s briefly review what the Great Barrington Declaration is and what its effects have been before moving on to the study itself.
The Great Barrington Declaration: Propaganda, not science
I’ve written a number of times about the Great Barrington Declaration, a document written by three “lockdown” hating scientists recruited for a meet-and-greet with sympathetic journalists at the headquarters of the American Institute for Economic Research (AIER), a right wing “free market” think tank in Great Barrington, MA, the town that gave the declaration its name. The basic idea behind the Great Barrington Declaration, which was published in early October 2020, was that “lockdowns” were doing more harm than COVID-19. Based on this premise, the authors (Profs. Martin Kulldorff, then faculty at Harvard University, Jay Bhattacharya of Stanford University, and Sunetra Gupta of Oxford University) proposed, in essence, a “let ‘er rip” strategy for COVID-19 in order to reach “natural herd immunity” more rapidly by infecting those least likely to die from the disease. The idea was to lift protections and let the young and “healthy” go back to “normal life,” while using “focused protection” to keep the elderly and those with chronic health conditions who were at much higher risk for severe disease and death from contracting COVID-19.
As I originally wrote the very first time I discussed the Great Barrington Declaration, the idea of “focused protection” was long on claimed benefits but very short on policy specifics regarding how, exactly, those vulnerable to the worst outcomes from COVID-19 infection would be “protected” while ignoring that, even among the “low risk” population, a “let ‘er rip” policy like that espoused by the Great Barrington Declaration authors would still result in mass death and morbidity. Indeed, a number of respected public health scientists responded with the John Snow Memorandum, which argued that mass infection was not a viable strategy and explained why “let ‘er rip” would be far more harmful than letting the young develop “natural immunity” (more appropriately referred to as postinfection immunity) in a strategy to speed the achievement of “natural herd immunity.” (For a detailed explanation why the Great Barrington Declaration couldn’t have worked, I recommend this article, as well as an BMJ Rapid Response written by a Local Councillor in the UK who described in detail the practicalities that would have made a “focused protection” strategy almost certain to fail.
The Great Barrington Declaration was what I referred to as “magnified minority”; i.e., a document written by fringe physicians and/or scientists and then signed by a lot of other physicians and/or scientists in order to give the impression that the statements in the document are scientifically worthy of consideration. For purposes of the propaganda value of such a document, it doesn’t matter one whit if the signatories have the relevant expertise or not; all that matters is that they have advanced degrees after their names, in order to give the appearance to the public that a large number of experts endorse the document. Moreover, “magnified minority” is a common tactic by science deniers and has been used by, for example, cranks who claim that HIV doesn’t cause AIDS, climate science deniers, and evolutionists. (Does anyone remember Scientific Dissent from Darwinism?)
The Great Barrington Declaration was the same tactic. It was also profoundly eugenicist, as I argued right from the start, in that it left the elderly and those with chronic illnesses to the tender mercies of SARS-CoV-2 while only paying lip service to actually protecting them. This was especially true in October 2020, a time when it was generally thought that a safe and effective vaccine against COVID-19 wouldn’t be available for at least a few more months. Even though the Pfizer vaccine did roll out two months later in December, quantities were very limited at first, with availability limited to healthcare and other frontline workers until well into early 2021.
Unfortunately, Great Barrington Declaration supporters, despite their constant claims of “persecution” and being “silenced,” basically won the PR and policy battle. In 2020, its authors easily gained access to the highest levels of government in the US and Europe to argue against “lockdowns,” and Jeffrey Tucker left the AIER to spawn another right wing think tank, the Brownstone Institute, which he lovingly characterized as the “spiritual child” of the Great Barrington Declaration and for which he recruited Martin Kulldorff as scientific director. AIER, Brownstone Institute, and a host of other “free market” anti-regulation astroturf rapidly became the new merchants of doubt about public health and struck back at critics who pointed out the connections between right wing think tanks and anti-public health activities increasingly linked to the far right and its media ecosystem.
Even worse, increasingly the Brownstone Institute and others promoting the Great Barrington Declaration are spreading misinformation that is more and more explicitly antivaccine and attacking vaccine advocates on social media while portraying vaccine and mask mandates, as well as “lockdowns,” as slavery, religion, fascism, and Communism, apparently depending on what day of the week it is. You’d think that there is no greater tool for a “focused protection” strategy than a safe and effective vaccine against COVID-19 and that Great Barrington Declaration authors and advocates would want to encourage vaccination of as many people as possible. You’d be mistaken. At least two of the authors, plus the founder of the Brownstone Institute, have openly embraced fantasies of retribution against public health advocates very much like the sorts of fantasies of retribution antivaxxers have held for decades, in particular the idea of a “Nuremberg 2.0,” a Nuremberg-style tribunal in which public health advocates will “be held accountable” for their supposed “crimes.”
Of course, it’s obvious in retrospect that a “natural herd immunity strategy would never have worked. One has only to cite the rise of the Delta and the Omicron variants, the latter of which has been able to overcome vaccine-induced immunity in many people but postinfection immunity as well. Even without the rise of these variants, an entirely predictable event when a virus circulates in a large enough immunologically naive population for long enough, no disease has ever been controlled solely through “natural herd immunity.” Other measures, especially vaccines, are necessary. Worse, even if COVID-19 could have been controlled through a “natural herd immunity” approach, the death toll would have been even more horrific than it already has been, given that the US alone has suffered close to a million fatalities (almost certainly a gross underestimate), and the world many times that.
Which brings us back to the study, Critical weaknesses in shielding strategies for COVID-19, published by Smith et al in PLoS Global Public Health a couple of days ago. Kit Yates, whose Tweets I quoted, is a coauthor.
“Focused protection” wouldn’t have worked
This paper was written by a group from the University of Bath in the UK consisting of Cameron Smith, Christian Yates, and Ben Ashby. The first thing you need to know is that they’re all in the Department of Mathematical Sciences and that this is a modeling paper. Another interesting thing, looking at the metrics of the article, is that the study, although covered fairly widely in the press, didn’t achieve nearly the coverage in the press or social media that a number of highly dubious papers that amplified COVID-19 contrarian takes on the pandemic. (Just compare the metrics for John Ioannidis’ math-challenged “science Kardashians” article or Paul Thacker’s “Pfizer whistleblower” conspiracy theory article months after their publication if you don’t believe me.)
The other interesting thing is that the model, based on real world data, appears to support what I’ve always intuitively thought about the Great Barrington Declaration, namely that it would require perfection to have even a hope that “focused protection” would work. After all, the elderly and many with comorbidities who are at the highest risk of hospitalization and death from COVID-19 require care (or at least help) from the young and “healthy” population in which “natural herd immunity” is being sought. Think about it. All it takes is one infection in a nursing home to start an outbreak that could kill many of its frail residents. We’ve seen it. The same is true for any multigenerational house in which elderly or chronically ill people live with younger “healthy” family members who provide some level of care to them. How do you keep the contact between, say, a parent with early stage Alzheimer’s disease living with their adult child who cares from them, to zero? You can’t; that is, unless one or the other moves out.
In their introduction, the authors provide this rationale for their study:
Prior to (and during) the rollout of vaccines, most countries introduced a range of non-pharmaceutical interventions (NPIs) to bring infections under control, including social distancing, travel restrictions, and lockdowns. While the effectiveness of different NPIs has varied within and between populations and over time, they have been largely effective at bringing outbreaks under control [2–4]. A widely discussed alternative approach would have been to limit most NPIs to the most vulnerable subpopulations while allowing those at lower risk to live with few or no restrictions [4–6]. ‘Shielding’ (or ‘focused protection’), appeared to offer the possibility of avoiding the various societal costs of universal NPIs by leveraging the uneven risk profile of COVID-19, which is heavily skewed towards the elderly and those with certain pre-existing conditions [7, 8]. In theory, by allowing infections to spread with little to no suppression among the lower-risk population during a temporary shielding phase, the higher-risk population would subsequently be protected by herd immunity . Several countries either openly or reportedly embraced this strategy during the early stages of the pandemic. Sweden, for example, chose to impose few restrictions on the general population while banning visits to long-term care (LTC) facilities , and the UK initially appeared to opt for a shielding strategy  before implementing a national lockdown. In the autumn of 2020, many countries experienced a resurgence in infections following the lifting of NPIs, leading to a renewed debate about the merits of shielding, driven by the Great Barrington Declaration which called for “focused protection of older people and other high-risk groups” while allowing uncontrolled viral transmission among lower-risk individuals [12, 13].
However, they also note:
It is important to retrospectively assess the feasibility of shielding as a public health strategy, not only for public inquiries into COVID-19 and future pandemic preparedness, but also for countries where levels of vaccination remain low. Moreover, new variants may emerge which substantially escape vaccine-induced immunity, thus requiring a renewed choice between lockdowns and shielding while vaccines are updated. Although superficially appealing, serious practical and ethical concerns have been raised about shielding as a strategy to mitigate the impact of COVID-19 . Yet there has been little mathematical modelling to determine the effectiveness of shielding under realistic conditions [4–6]. Crucially, the combined consequences of imperfect shielding, uneven distributions of immunity, and changes in contact behaviour among lower-risk individuals have yet to be explored.
So explore them the authors did, using a model designed to simulate early stages of a pandemic, when the virus encounters an immunologically naïve population for the first time, with the following parameters and assumptions:
Our model is loosely based on an idealized large city in England (although our qualitative results would apply to similar countries) consisting of 1 million people, 7% of whom are at higher-risk of mortality from COVID-19, with 10% of higher-risk individuals situated in LTC facilities [15, 16]. We compare epidemics under no shielding, with imperfect (partial reduction in contacts for higher-risk individuals) and perfect shielding (no contacts for higher-risk individuals), with shielding restrictions lifted when cases fall below a given threshold (see §2.1).
To address the question of whether a Great Barrington Declaration-like “focused protection” strategy could have worked, the authors modeled a hypothetical large city in England with a population of one million, using an SEIR (Susceptible, Exposed, Infected, Removed) model. They compared the outcomes from no shielding, with imperfect and perfect shielding, with shielding restrictions lifted when cases fall below a given threshold. The framework for the model looks like this:
The mathematical analysis is quite complex, as you might imagine, and I’m sure there are mathematicians who could critique it much better than I. In any event, the first finding is that, in theory, it is possible that a Great Barrington Declaration-like “focused protection” approach could have worked to keep the most vulnerable from dying in droves. There are some serious problems, though. First, the protection would have had to have been perfect, with 0% contact between the “healthy” out there catching COVID-19 for the greater good of achieving “natural herd immunity” faster and those who, through either age or chronic health conditions, were at much higher risk of dying from the disease. Basically, the level of shielding would, as a practical matter, have been impossible to achieve, which means that infections from the lower-risk population would have inevitably leaked through “focused protection” to the vulnerable.The second problem is that, even assuming the most optimistic conditions, hospitals would have been completely overwhelmed—by at least ten-fold!—by the first wave of infections. In addition, even if the lower risk people out there catching COVID-19 to achieve “natural herd immunity” started reducing social contact to avoid infection, thus slowing the increase in case numbers and thereby taking some pressure off of the hospitals, the model suggests that it would likely have been impossible to achieve “natural herd immunity,” which would have made a second wave of infections after shielding ended almost inevitable. Moreover “natural immunity” would have been unevenly distributed in the population, which would have led to the risk of local outbreaks.
Or, as the authors put it:
Our results demonstrate critical epidemiological weaknesses in shielding strategies that aim to achieve herd immunity by isolating the vulnerable while allowing infections to spread among lower-risk members of the population. While our main results focus on a limited set of parameters, our findings are qualitatively robust to sensitivity analysis (§A of the S1 Text). Even in the best-case scenario with perfect shielding, our model estimates that there would have been tens of thousands of avoidable deaths among those deemed to be at lower risk due to limited mitigation in this subpopulation, even without accounting for the rapid depletion of healthcare capacity. A significant reduction in contact rates would have been required to avoid overwhelming healthcare capacity during shielding , but the population would have then failed to achieve herd immunity, allowing a second, deadlier wave to occur following the lifting of restrictions. Under more realistic assumptions of imperfect shielding, our model estimates that deaths would have been 150% to 300% higher compared to perfect shielding.
Our model demonstrates that shielding would have only worked well under practically unrealizable conditions. If any of these conditions had not been met, then significant outbreaks would have occurred in higher-risk subpopulations, leading to many more deaths than if shielding were perfect. To be effective, shielding would have also required those who were at higher risk to not only be rapidly and accurately identified, but also to shield themselves for an indefinite period. If higher-risk individuals were to be misdiagnosed or were unable to fully isolate this would have decreased the effectiveness of shielding. For example, shielding would have been especially difficult for households that contained both higher- and lower-risk individuals (e.g., 74% of CEV people in England live with other people, and 15% live with children aged under 16 years ). The large number of multi-risk households suggests that either shielding would have been far from perfect, or a significant proportion of lower-risk individuals would have also had to shield, in which case it would have been harder (or perhaps impossible) to achieve herd immunity during the shielding phase.
In practice, according to this model, the Great Barrington Declaration would have been a disaster.
It’s only a model, but it’s a best case scenario model
But, but, but, but… you say (and Great Barrington Declaration supporters retort), it’s only a model! Yes, it is. It’s a model. However, that doesn’t help Great Barrington Declaration fans, because this is actually a model that is based on some pretty optimistic assumptions. Indeed, the authors appear to have gone out of their way to use assumptions that were conservative, best case scenarios even.
As the authors note:
Our model also made conservative assumptions regarding infection fatality rates (IFRs; see §2.1) and immunity, but more realistic assumptions are likely to make the case for shielding far worse. For example, we used relatively low estimates for the IFRs and assumed that these were fixed even though healthcare capacity would have been significantly overwhelmed under all shielding scenarios. The model also did not capture the impact of healthcare burden on mortality from other causes.
Again, these are all very optimistic assumptions.
Even worse (for the Great Barrington Declaration, not the model), the authors note that the model did not take into account the potential evolution of SARS-CoV-2:
A large epidemic would have also potentially allowed new variants to emerge, which may have been more transmissible, more deadly, or able to escape immunity. We made the conservative assumption of no pathogen evolution, but novel variants would have rendered shielding an even less effective strategy.
We know that variants arose that fulfilled two out of those three criteria. The Delta and Omicron variants were not more deadly than the original strain, but they were more transmissible and—especially the Omicron variants—better at evading immunity. The Delta variant arose last summer and was much more transmissible than the original Wuhan strain. It was followed by the Omicron variants this winter, which were even more transmissible and able to evade prior immunity, leading to many more “breakthrough” infections after vaccination and to reinfections in those who had recovered from COVID-19.
It’s long been pointed out that the fatal flaw in the thinking (if you can call it that) behind the Great Barrington Declaration is that it never took into account what virologists knew even in October 2020 to be the high likelihood that new variants would arise that were more transmissible and possibly even able to evade immunity due to prior infection. (Again, remember that the Great Barrington Declaration was written months before vaccines started rolling out to the population in large quantities, and then primarily in developed nations.) This model assumes what Great Barrington Declaration signatories apparently actually believe, even though it’s not true:
We further assumed that immunity from infection was perfect and long-lasting (‘best-case’ assumptions for shielding), but neither is likely to be true in reality
We now know that immunity from infection was robust but nowhere near long lasting, as evidenced by the number of reinfections. As I’ve discussed before, “natural immunity” due to infection doesn’t appear to be much longer lasting than vaccine-induced immunity.
All of this is why the authors concluded:
These additional considerations, in combination with the clear flaws indicated by our modelling, suggest that, while an idealized shielding strategy may have allowed populations to achieve herd immunity with fewer deaths, they are likely to have failed catastrophically in practice.
A good rule of thumb is that a strategy that requires perfect execution in order to have a chance of working is a strategy that is not going to work.That describes the Great Barrington Declaration very well. Of course, the Great Barrington Declaration was never a serious strategy. It was propaganda with a veneer of science just convincing enough to sound reasonable to people without a lot of knowledge of infections disease, epidemiology, or public health, whose understanding of “herd immunity” is superficial, and its purpose was to provide a seemingly scientific rationale to do what right wing “free market” groups wanted to do anyway: Stop business closures and government public health restrictions and mandates. Stop collective action in the service of public health. Weaken the administrative state.
Unfortunately, the astroturf groups manipulating useful idiots like Martin Kulldorff into producing the Great Barrington Declaration succeeded wildly, no matter how much Kulldorff and his crew whine about being “silenced” and fantasize about retribution against public health advocates or AIER portrays itself as akin to persecuted abolitionists.
Of course, the Great Barrington Declaration was never a viable plan to deal with the pandemic. It was never intended to be and didn’t have to be. It was propaganda all along.