What about this "Great Barrington Declaration" suggesting we seek fast herd immunity?

Updated: Oct 17

Three scientists, Dr. Martin Kulldorff from Harvard, Dr. Sunetra Gupta from Oxford, and Dr. Jay Bhattacharya from Stanford, have written a "Great Barrington Declaration" that has now been signed by a number of medical and public health scientists and other people.


Motivated by the collateral damage caused by lockdowns, it promotes and alternative strategy to pandemic management that involves "focused protection" of vulnerable populations, including older people and those with pre-existing conditions predisposing them for poor outcome if infected, and otherwise allowing the rest of their population to live their lives without restriction, hoping to accelerate towards "herd immunity", the point at which a high enough proportion of the society has been infected that the virus can no longer spread in epidemic fashion. You can hear the three originators of this declaration in a YouTube interview by UnHerd.


This has received a reasonable level of of attention since it was posted on October 4, and generated a considerable degree of controversy.


It clearly flies in the face of the current orthodoxy of pandemic management that involves working to limit viral spread through a series of precautionary steps including mask-wearing, physical distancing, and selective closures of businesses and schools depending on local transmission levels, reserving the right to induce stay-at-home orders or additional closures should the viral transmission rates become too high. The ultimate goal would be to reduce viral levels to the point at which viral levels were at a low enough level such that testing, contact tracing, and targeted isolation would keep the virus completely under control.


In my own view, I agree with this group that the collateral damage of some of these mitigation strategies have not been adequately considered and weighted against the benefits they provide. I believe lockdowns can only be used for a short period of time, 2-3 months at the very longest. I believe that extensive stay-at-home orders have led many to not seek prompt medical care for important non-covid conditions, leading to unnecessary morbidity and mortality, and that school closings can have a deleterious effect on children's education and psychological well-being, and that extended closures of businesses has led to failing of numerous small businesses and provided financial hardship to many whose livelihoods are dependent on these businesses. Thus, I agree that it is important when formulating viral mitigation strategies one must not just think of the single dimension of minimizing viral spread, but think multi-dimensionally, trying to minimize spread while taking into account the collateral damage of each step through a careful cost-benefit analysis.


I also agree with them that it is well established that the mortality risk for COVID-19 is heavily concentrated in the high risk group, and the probability of death is negligible for young, healthy people if infected. This differential risk is not taken into account enough in formulation of pandemic strategies. As they propose, we should certainly take extra steps to protect the vulnerable populations at highest risk of poor outcomes. Indeed, our failure to do so has contributed to a large number of the deaths we have experienced, roughly 40% of deaths in the USA coming from nursing homes and other long term care facilities.


I also agree that "herd immunity" is not a controversial idea, but rather a goal in viral management. This is the mechanism by which vaccines attempt to eliminate viral threats in a society, and indeed a combination of vaccinated individuals and infected and recovered individuals can comprise the numbers needed to reach herd immunity.


So, while I believe there is merit in some of their motivating principles and that these principles are under-appreciated by our current pandemic response orthodoxy, I strongly disagree with their specific recommendations, think there are key factors they are not taking into account, and believe their strategy would be disastrous if followed.


The key problem I have is their suggestion that, with the exception of the vulnerable populations, society should eagerly seek to reach herd immunity as soon as possible. Thus, they do not agree with individuals following mitigation strategies such as mask wearing or social distancing, nor do they agree with shutting down environments that might be prone to super-spread events. They consider these steps as just delaying the inevitable, and extending the pain caused by the pandemic.


There are a number of assumptions underlying their declaration that may not hold and, if not, threaten their proposed outcomes:

  • Hospitals will not become overwhelmed and lead to unnecessary mortality and morbidity.

  • Infections will lead to mostly mild symptoms in the young, healthy population.

  • There will not be any long-term health effects for recovered individuals.

  • We will be able to keep the spread from reaching the vulnerable populations.

  • Under this strategy, herd immunity will be reached within 3 months.

I will briefly discuss each of these:

Hospitals will not be overwhelmed: if their strategy were followed, by design there would be massive surges of infections all over the country. If vulnerable populations are adequately protected, it is true that many of the infections would only have mild symptoms, but given a massive surge even a small proportion of severe disease requiring hospitalization could overwhelm local healthcare systems in many regions. Even now, with stronger mitigation strategies in place, there are hospital systems overwhelmed by the current surge, for example Wisconsin has opened field hospitals to handle the overflow. Analyses I have seen (unpublished yet) have shown that mortality rates increased from March to April as hospitals became overwhelmed, and allowing unconstrained viral spread is likely to lead to unnecessary morbidity and mortality.


Infections will lead to mostly mild disease in these populations: It can be shown (unpublished data) that severity of disease, as measured by rate of severe disease and death, has decreased from the Spring into the summer. It is likely that the mitigation strategies of distancing and mask-wearing has substantially contributed to this reduction. Even when not enough to prevent transmission, these strategies clearly reduce the inoculum received by an infected individual, and there is strong evidence that reduced inoculum tends to produce more mild disease. Discouraging mask-wearing and distancing might not just lead to faster viral spread, but might result in increased inoculum in those who become infected, leading to a higher proportion with severe disease and risk of death, even among those in the young, healthy demographic.


There will not be long-term health consequences for recovered individuals: Like many viewpoints that I believe undersell the risk of the virus, their proposal considers death as the only substantial risk of infection. This ignores growing evidence that with SARS-CoV-2, unlike other common viruses like influenza and common cold, can lead to significant long-term complications in many recovered individuals. There are numerous reports of individuals experiencing long-term deleterious symptoms, so-called "long haulers", often caused by inflammatory dysregulation lasting after the immune system has worked to remove the virus. There are also reports of numerous individuals experiencing myocarditis, or inflammation of the heart, after recovery. This potentially long-term and life-threatening complication has been observed in a substantial proportion of recovered individuals, even young, health athletes. While not enough is known about the frequency or duration of these complications, it is enough to give us pause about the wisdom of inviting the virus to "rip through" the young, healthy population. If these complications are common and long-lasting, such a strategy could be disastrous.


We will be able to keep the spread from reaching the vulnerable populations. The idea of "focused protection" sounds simple enough: we know who the vulnerable populations are -- we just need to isolate and protect them and they will be safe from the viral surge ripping through the rest of society. They propose that nursing homes be staffed by people with immunity or who are tested frequently to ensure they are not infected. However, given the known high false negative rate of SARS-CoV-2 tests in asymptomatic individuals who were recently infected (but still contagious), it is not clear whether this strategy will indeed keep the residents safe from the virus, especially if it is allowed to spread unconstrained in the broader society. The high viral levels in the general society increase the risk of it spilling over into the vulnerable populations, even if testing is done, given the high false negative rates. Indeed, inviting high societal viral levels unavoidably increases the probability of it reaching the vulnerable populations as well.


Herd immunity will be reached within 3 months. In their interview linked above, they confidently assert that given SARS-CoV-2's R0 rate and mathematical modeling of infectious disease spread, this strategy would produce herd immunity within 3 months as the virus would peak and wane during that timeframe. However, this fails to take into account that not everyone in society will be so eager to be infected and stop practicing the recommended mitigation strategies of mask wearing and distancing, and in fact it is expected a substantial proportion of society would continue practicing these measures no matter what strategy is proposed by scientists or government leaders. This would slow the movement towards herd immunity and make it extremely unlikely we could reach the required 60-70% prevalence within 3 months.


For this reason, I will not be signing their declaration, and believe it is misguided and dangerous.


My view, as well documented on this blog since early April, has been that lockdowns are not sustainable, but just short-term tools to slam down viral levels to enable stronger control strategies. Once the lockdowns went for 6 weeks, I argued that we needed to transition to targeted mitigation strategies -- that we had learned enough to assemble a set of guidelines that, if followed, could constrain viral growth yet minimize collateral damage to society. This includes broad mask-wearing, physical distancing, and decrowding indoor settings, and focusing any closures on settings ripe for super-spread -- crowded, enclosed indoor settings with potentially poor ventilation. I have argued that schools need to be opened as soon as possible, with the timing based on local viral levels, and equipping schools with resources for fast testing, contact tracing and targeted isolation to prevent any school-based surges.


I still believe this is the best strategy. I support a broad reopening of schools and the economy, but think we need to spend considerable effort in urging people to take basic precautions that will limit the rate of spread and reduce inoculum to reduce severity of disease in those infected -- the mask wearing, distancing, and avoiding crowded indoor locations. If we do these things while reopening, we have the chance to keep viral spread low enough so hospitals are not overwhelmed, to continue to reduce inoculum to hopefully keep the rate of severe disease low, and by keeping community viral levels low, have a better chance of protecting the vulnerable populations.


I have seen some suggest that their failure to pay lip service to masking, distancing, indoor de-crowding, and other targeted mitigation strategies as an oversight. I strongly disagree. If you listen to them, it is clear that their philosophy does not value these targeted mitigation strategies, but rather sees them as unnecessary and delaying their stated goal of natural herd immunity. It is not an oversight but a deliberate feature of their viewpoint.


These steps will delay herd immunity, yes, but in spite of what the proponents of this Great Barrington Declaration say, I believe this delay is a positive not a negative. Why should we be in a hurry to reach herd immunity naturally when we have so many promising vaccines under development, some of which might be ready for delivery as soon as this winter? These would provide the opportunity to reach herd immunity without as much mortality and morbidity, and minimizing the number of infected individuals who might have to deal with long-term post-covid complications. What is the rush? Seeking rapid natural herd immunity discounts the potential benefits of vaccines and underestimates the potential long-term damage that can be caused by "natural infections."


There is definitely a contingent in society that is too risk-averse and too scared of the virus, the group I dub the "alarmists" in my previous blog posts, and I think it is important that our mitigation strategies are not driven by these individuals who do not adequately consider the collateral damage caused by mitigation strategies or fail to recognize the appropriate level of risk that infection poses for different groups of people. I do think that much of our pandemic management orthodoxy is driven by this perspective, and is rigidly intolerant of any questioning of its wisdom, quickly labelling anyone who opposes these viewpoints as reckless. We need more open discussion of cost-benefit and sustainability of our long-term mitigation strategies. However, there is also a contingent that underestimates the risk the virus poses, the so-called "deniers" or "doubters", and I believe that the scientists who originated the Great Barrington Declaration fall on that end of the continuum, ..., a little too far for my taste.



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