Coronavirus #6: "Herd Immunity" and Opening Up
The more I cruise the internet, the more I read about “herd immunity.” The term is not new to me; I have known about herd immunity since my immunology course in medical school back in 1994. Herd immunity is defined as the point at which a high enough percentage of a population is immune to a disease that the collective immunity will prevent the disease from spreading from person to person. The underlying idea is that everyone in a community doesn’t have to be immune for the community as a whole to be immune — if most people are immune, the people who are not immune will be shielded from infection by the people surrounding them who cannot be infected.
The percentage of people who must be immune for herd immunity to take effect varies with the contagiousness of the disease. The flu will often achieve herd immunity when 60-70% of the population is vaccinated. The measles, which is far more contagious, can still spread if any less than 90% of the population is vaccinated. With COVID-19 it is not known what the percentage has to be because its precise infectivity is not yet known, but based on the data so far, it is thought that herd immunity will be achieved at about 60-70%. However, estimates range from a high of 80% to lower than 40%. But the truth is that we do not know.
Prior to COVID, when I encountered the term herd immunity, what was being discussed was how many people needed to be vaccinated to prevent an epidemic. That is to say, herd immunity has always been a way to look at vaccination rates. This, however, is not the way it tends to get used with regard to COVID-19 — instead, most people are asking how many people have to get infected before new infections will stop.
And this is the worst way to look at it. Asking how many people have to get sick for the pandemic to end is like asking how much of the forest has to burn before the fire goes out on its own. Anyone can see that of all ways to handle a disaster, the worst approach is to ask what is the absolute worst that can happen if we do nothing, and then label that as Option One. If this is our approach, we are consciously choosing to accept the worst of all outcomes in a situation where we clearly have many options to choose from. Even the second worst option — say, everyone wearing a mask — would be superior to the one we seem to be pursing.
So far, with COVID-19 we have not only done the worst thing possible in opening up too soon and allowing the disease to rage worse than ever, but we have also paid out $2.4 trillion in bailouts in the process. Thus, we have an explosion of new cases in July after burning through trillions in borrowed money, when we could have had the same explosion in April for free. And letting the world burn down in April would have at least given us a shot at a clean school opening by September — something looking now like more of a pipe dream with each passing day.
I focus on the misuse of the term herd immunity because it is emblematic of the total failure of the U.S. government to manage COVID. Medicine did not coin the term so it could be used to calculate the maximum damage an epidemic can cause before it burns out. Medicine — don’t let this shock you — is in the business of minimizing suffering, not allowing it to max out. Medicine can’t always cure illness, but it almost always has a mitigation strategy.
The misappropriation of the term herd immunity shows that politicians, and to a large extent the American people, are more concerned about saving money than about relieving suffering. No one said we had to do absolutely everything to stop COVID, but medicine did at one time have a portfolio of options to make the suffering less, from isolating the most vulnerable and eliminating the highest risk behavior on down to shutting everything down so completely that the disease was bound to die out.
Instead of pursuing a real plan to the end, we opted for something like a 75% shutdown that was 25% shorter than it needed to be. And as would be expected when you take a lower than recommended dose of medicine for less time than you were supposed to, you end up back at the beginning, having accomplished nothing. Today we are back where we were on April 1, and faced with finding out what herd immunity looks like the hard way.
As of this writing the number of cases are skyrocketing, but the death rate is not. At least not yet. There are a variety of reasons why this could be true. It could be that COVID is now infecting more young people, resulting in fewer deaths. Or that the virus has mutated and is not as virulent as it used to be. It is also possible that doctors are getting better at treating the disease (although as a doctor on the front lines, I don’t believe this one is likely to be the most significant factor). Or it could be that the impact of the latest surge has not come yet. Remember that it takes 3-4 weeks after initial infection for COVID to kill.
But it doesn’t matter. COVID will be enormously disruptive and expensive, far more disruptive than it needed to be. We knew enough about this in April to do what had to be done. We just didn’t do it.
Medicine is an observational science. We look and learn. We search for signs of a disease and its progress, and we react to it in real time and try to stop it. What we don’t do is sit around and see how bad a disease is going to get before deciding if intervening is too expensive. But that’s what your elected officials have done. They looked at the remedy, decided it was too expensive, and chose to roll the dice. The price is $2.4 trillion and counting, and all we have to show for our trouble is overwhelmed hospitals and the danger that we will open our schools in the fall while the virus is absolutely everywhere.
I don’t know about you, but I don’t consider these results acceptable. And it doesn’t do much good for my morale as a doctor to know that I am working daily to clean up the mess that America at large lacked the will to get under control when it had a chance. Our government could have done much better. All we can do now is start over, listen to the experts this time, bury the dead, and vote how we feel about it in November.
