The Poisoned Chalice Of Controlled Herd Immunity
It was only a month ago when I was casually discussing the Coronavirus with an acquaintance who works as a GP and they said something that surprised me.
“In a few months time, immunity to the disease will be the greatest asset anyone could have, those still locked inside will see their friends who have recovered, out in the world and wish they had gotten the virus earlier. For young people like yourself, there is no risk in getting it earlier…”
Countries around the world are discussing antibody tests that will allow the recovered to get back to work¹. What happens if after months of flattening the curve people have an incentive to become infected? Will this be a problem, and how can it be stopped?
Is it possible to slowly infect young, healthy individuals in a controlled and safe manner, and help lift the country out of a Depression?
Having crushed the curve, Australia is in a unique position. Unlike the USA, China, India and most of Europe who was forced into month-long lockdowns, Australia can choose its destiny. Soon the rest of the world will be facing similar decisions.
The pattern seen in Australia is repeated across the world. The drop in cases is so significant and so dramatic that one might be naively tempted to declare victory. The stock markets are already sounding victory, the S&P500 up more than 20% from the bottom only weeks ago. This is naive. Assuming the virus cannot be eradicated entirely, Australia and the rest of the world will still have a long road ahead.
Currently, the economy is in a coma, and the money printers of Central Banks are whirring to keep the life support on. The situation that gave the world this unprecedented victory is not sustainable. To improve the economy you need to lessen the lockdown. With the relaxation of laws comes great risk. No rule states that the once you’ve flattened curve once, it can’t shoot straight back up.
Six months is the diagnosis according to Australian Prime Minister, Scott Morrison. Six months, before the unprecedented $130 billion cash injection into the hands of the unemployed is cancelled and the economy is left to run on its own merits. Every week beyond this will either require billions of additional government spending or cause the nation with the second-highest level of household debt² to crumble. Other countries like the US probably have less time up their sleeve.
So what is going to change?
In 18 months we can except a vaccine³. This is our worst-case scenario, but we can’t live in lockdown that long. It simply isn’t tenable, a Depression would be inevitable. While trading off lives for the economy can seem heartless, the suffering associated with economic catastrophe is immense and cannot be ignored. Some argue that anti-virals, not lockdown could provide the cure, but it is entirely uncertain what benefit they will bring and when. Medicines such as remdesivir and hydroxychloroquine have shown potential but their efficacy is still unknown.
The world can either lockdown for 18 months and watch the economy disintegrate or slowly lessen restrictions as more people recover and immunity rises. Why not speed this up?
Herd immunity was initially the strategy of the United Kingdom before they rightly lambasted for their ignorance and thankfully changed course. Sweden is currently ploughing forward with an uncontrolled herd immunity strategy. Herd immunity cannot be applied haphazardly. If countries are considering this path, absolute control is essential.
Young people who are superspreaders of the disease. Immunising this demographic could be the key to success. For those under the age of 40, the fatality rate is estimated to be only 0.09%⁴, with most infected displaying only mild symptoms. Across the world, there are millions of empty hotel rooms and millions of young people who could fill them. Indeed, hotels are being used as quarantine accommodation across the world as we speak.
We must ask ourselves. Is it possible to deliberately infect, young, consenting, healthy, low-risk adults with a low viral load in a controlled setting and immediately isolate them until they have recovered? If feasible, such a strategy could be rolled out across the globe.
To properly evaluate the efficacy of this policy we must look at the risks and the rewards.
Given everyone’s absolute devotion to trying to “flatten the curve”, directly infecting healthy people may seem absurd, dangerous and unethical. However, we must remember that the whole purpose of “flattening the curve” is twofold:
- To reduce strain on medical resources
- To buy time to increase medical resources
One of the best ways to “flatten the curve” and reduce strain on medical resources is to reduce transmission between at-risk groups by as-symptomatic carriers.
In South Korea, high levels of testing show that almost a third of all cases are between the ages of 20–29. In Italy, this figure is likely lower because the young often show no or mild symptoms. This hypothesis is strengthened by a small randomised study in Iceland concluded that 50% of coronavirus cases are as-symptomatic⁵.
Increased herd immunity within this age group will drastically slow the transmission of the disease through vulnerable communities, thus flattening the curve in the long run.
Infecting the healthy in a controlled manner before isolating will slightly increase demand on these resources in the short term as a tiny slither may require medical aid. These short terms risks are manageable and pale in comparison to the long-run benefits
In the case of an uncontrolled outbreak in the public, such a scheme can be immediately scaled back to redirect resources. If it is successful, it can be scaled up to give natural immunity to more people⁶. Given the fact that medical resources are not currently strained, Australia is in a unique position to implement such a program.
Not only will this proposal work to flatten the curve, but it will provide invaluable data to the epidemiologists and policymakers that will save countless lives across Australia and the globe. What percentage of young people are asymptomatic? What treatments help alleviate symptoms? This would be a scientifically robust way to find out.
It is only a matter of time before young people, who bear the majority of the economic and social cost and are exposed to the least risk realise that getting the disease is in their own best interest. Blood tests that can determine who is immune and can return safely to society and work could be rolled out across America as early as next week⁷. In a stratified society divided into the working immune and the idle dangerous, what happens when people have the incentive to become infected? This policy negates this risk.
The incredible power in this solution lies in the control that it gives policymaker and doctors. The default policy of allowing slow, haphazard infection of random individuals (including the vulnerable) using police-state lockdown laws as breaks is not sustainable. It is dangerous and chaotic. It is far more effective to increase herd immunity safely while we have the chance.
This policy will not get us all the way there, however, it will open opportunities for thousands, flatten the curve and allow for life to get back to something that resembles normal far earlier than waiting for a vaccine.
The pivotal fulcrum on which the herd immunity route turns on is the case fatality rate of the coronavirus and how representative this is of the true number of infections. For herd immunity to be a factor the virus would need to be significantly widespread and less deadly than studies suggest⁸. For population immunity to be effective without being accompanied by significant social and government-enforced restrictions, population immunity must significant. There is a significant risk in trying to develop population immunity that you don’t reach a level where the effect is significant enough to warrant re-opening the economy.
The is another option. Stop the virus at the source with widespread testing and common-sense restrictions. By banning superspreader events, wearing masks, forensically tracking infections and implementing widespread testing the virus can be kept at bay indefinitely without superdestructive lockdowns or killing thousands in the search for Herd immunity.
Prior to the first significant restrictions in Australia when bars, restaurant and gyms were closed indefinitely the 23rd of March, the effective reproductive number was already below the critical threshold of 1….Whether it be widespread testing, wearing masks or cultivating socially responsible culture, Australia, Sweden and South Korea have shown it possible to reduce the reproductive rate of the virus without risking millions of lives or decimating the economy. The trade-off between herd immunity and health is naive. Using the SIR model it is possible to show that medium level immunity as developed in hard-hit areas like New York will give limited protection to future outbreaks without additional measures. Where medium level immunity fails, effective herd immunity can be developed by reducing the transmissibility of the disease. These methods are far more effective than mid-level immunity that comes at the cost of thousands of lives and economically destructive lockdowns. — R0 & The Economy
There is also a the low but very real risk that the government could be sanctioning the infection of young, healthy individuals with a disease that could cause devastating long term health conditions.
“Following infection, the virus will remain dormant (resting) in nerve cells near the spinal cord for the rest of the person’s life. Reactivation of this virus causes A blistering rash with band-like distribution, usually associated with severe pain. “ — Source: HealthSA
That quote is referencing chickenpox and shingles, not COVID-19. Although unlikely, there is no guarantee that something similar couldn’t occur with the coronavirus. We have no longitudinal data on this disease. Although the mechanisms are unclear, tests have revealed that the virus has been “reactivated” in dozens of recovered Korean patients⁹.
This also raises the most crucial argument that there is no guarantee that immunity is long-lasting in all patients who contract the virus. The ethical, economic and political consequences of allowing millions to be infected and thousands die for immunity that is short-lived or non-existent would be disastrous. There have been small, unreplicated, unconfirmed but worrying studies emerging from china showing that of patients discharged from the Shanghai Public Health Clinical Centre, nearly a third had unexpectedly low levels of antibodies. In some cases, antibodies could not be detected at all¹⁰.
The strongest argument for total herd immunity is an economic one. If Australians want to avoid being locked in their rooms while the economy craters and their income dwindles, some relaxation of constraints is necessary.
Previously we held up South Korea as a success story, but even they haven’t been able to escape the financial turmoil that the virus brought with it.
“Could dramatically increased testing rates and social changes halt the virus in its tracks? South Korea looks like a fanciful best-case scenario given that no western city on earth has the infrastructure that’s comparable….combined with over 8 million CCTV’s, South Korea is a disease tracking, surveillance state like no other. Still, this dream case holds a recession, as is likely the case for South Korea. Growth in the first quarter of 2020 was projected to be between -1.3% and -3.7% with little improvement on the horizon¹¹.” — Why The Market’s Optimism Is Naive
There is no silver bullet, there is an invisible killer virus infecting millions across the world and people are frightened. The economy will suffer, there is no escaping that. It is the degree of financially ruin that we do have control over. J.P. Morgan is now foreseeing a 40% decline in second-quarter GDP and the total US economy to still be more than 25% smaller by the end of the year¹². All of a sudden, a South Korean style mild recession is looking like a dream come true.
Korea can weather this storm because they made significant investments in its future and the safety of its people. The COVID-19 epidemic has been a wake-up call to western countries around the world who have not done the same. The world has exposed its Achilles heel and in the not too distant future countries will be seeking to expose it again. Terrorist groups, unstable nation-states or even a rising superpower could use CRISPR or other genetic engineering technology to engineer a virus of their own. This very real risk is outlined in a report published by the US National Academy of Sciences at the request of the Department of Defense¹³.
COVID-19 is not the first deadly contagion and it certainly will not be the last. During a lockdown, money vanishes into thin air. Western nations can avoid indefinite lockdown by investing in medical infrastructure. These tangible changes will provide insurance from future pandemics and discourage adversaries from investing in biological weapons.
Herd immunity inevitably requires a lockdown, most likely many of them. Not even Milan or New York are close to achieving it, even after thousands of deaths. If they were, the wouldn’t have needed to lockdown in the first place, the virus would have dissipated over time. Herd immunity seems like a risky way to burn money. Why not invest it?
There is no nobler a need than to put one’s own body in harm’s way for the greater good of the nation.
Should the government allow young people to improve their own lives while helping the nation?
In the case of total herd immunity, there is only one way to achieve it. Infect millions and kill thousands. In return for their sacrifice, the society is more robust to future outbreaks of this particular virus. On the contrary, in return for washing their hands, developing forensic disease tracking and widespread testing, society is robust to future outbreaks of all novel pathogens and bio-weapons.
Although herd immunity could deliver short term benefits to the economy the potential downside is catastrophic. When assessing risk you cannot base your decision off the most likely result, you must take into account the thick tail of unlikely but incredibly damaging consequences that could scare a nation for a generation. Together as a global community, we have an opportunity to invest in medical infrastructure that will save us from future disasters and perhaps discourage investment in the futures potentially most dangerous weapon, Biology.
The minimising of risk for public health and the economy has to be the ambition for all countries. Here the answer is clear. Herd immunity is an unknown entity and so is this virus. With great unknowns comes great risk. When it comes to the lives of our most vulnerable and an economy that would be shattered by a second set of lockdowns, now is not the time to spin the roulette wheel.