COVID-19 and “Herd Immunity”
Posted: April 28th, 2020 | Author: Scott | Filed under: Misc | Comments Off on COVID-19 and “Herd Immunity”I’ve heard a lot of takes, even from more mainstream and even “liberal” sources in the United States that the goal is to control the spread of the virus so it doesn’t overwhelm our health care system, but let it spread through the human population in some sort of “controlled” manner until we eventually reach “herd immunity”. I shouldn’t be surprised, I guess. We have deep eugenicist roots in this country. As I wrote elsewhere, the Nazis got a lot of their initial ideas and even laws directly from us. We had mandatory sterilization laws long before they were implemented in Germany and the last ones were not removed from the books until the 1950s. However, involuntary sterilization remains a legal practice in the United States to this day. It just normally requires a court order rather than a blanket law. A lot of race theory and the racism it supports is based on eugenics. Racism and eugenics are intertwined and threaded throughout our society.
So I shouldn’t be surprised. I know this is who we are. I know this is who we have always been. In this instance, though, the sheer callousness toward mass death and suffering astounds me. That’s what this perspective entails. Yes, the outcomes become immensely worse if our hospitals are overrun. The direct deaths from COVID-19 grow dramatically because there isn’t capacity to save everyone that could otherwise be saved. And because the health care system is overwhelmed all cause mortality also spikes. Lots more people die when the hospitals are overwhelmed.
But even if it were feasible to allow the virus to spread through the population without containment in some sort of controlled manner so that it did not overwhelm our hospitals, that would mean millions of people would die and millions upon millions more would suffer tremendously and some subset would have permanently damaged health and wellbeing from the disease. In the US, we have a population of 330 million people. The absolute best case is that COVID-19 has a 1% mortality rate. It could be as high as 3%-4%, but let’s assume the lowest possible estimate. That’s up to 3.3 million people dead. Let that number sink in. But it’s worse even than that. An estimated 10% of victims will be seriously ill and require hospitalization. The typical term of hospitalization is 10 or more days with incredible suffering. And we are already seeing that some of those who survive suffer permanent chronic and disabling effects. That’s not surprising. SARS-CoV-1 and MERS demonstrated the same thing. So that’s up to 33 million people hospitalized, on the verge of death, and possibly permanently disabled.
And that’s in the United States alone. With a global population of 7 billion, even if herd immunity could be achieved with as small a percentage as 60% of the population immune, that means at least 42 million people globally will die. As far as I’m concerned, anyone who can consider that an acceptable outcome is a morally deficient human being.
On this issue I wholly agree with Dr. Richard Beck in his post on moral fragility. “We like to think we’re moral, loving people. We are not. Our affluence had masked our depravity.” The fact that we have contemplated trading lives for money demonstrates that depravity, even if we ultimately move away from the morally reprehensible choice. However, we are not moving away from it. A significant portion of our citizenry, even crossing ideological lines, have embraced their depravity and are trying to justify it as somehow moral.
However, even for those willing to make that morally depraved tradeoff, it does not appear feasible to have some sort of controlled spread. This virus is far too contagious. I’ve been watching the estimates of the median rate of transmission creep up from day one and they started at levels supporting exponential curves. The rate of transmission is called R0 or R-naught. The R0 of a virus represents the median number of people each infected person will infect without any controls or mitigation in place. The most recent study I’ve seen has been prepublished by the CDC’s own journal, Emerging Infectious Diseases. It’s scheduled for the July issue so it is still in review and may change, but it’s as credible as any preprint can be.
High Contagiousness and Rapid Spread of Severe Acute Respiratory Syndrome Coronavirus 2
The study calculated an R0=5.7 for SARS-CoV-2. For comparison, seasonal flu has an R0=1.3. One of the most infectious diseases, measles, has an R0 of 12-18.
I want to let that sink in for a moment.
The first implication should be clear. The idea of controlled spread of a disease that contagious represents magical thinking. There is no way to allow slow, controlled spread through a population even if you’re willing to make the immoral trade of a large number of human lives for whatever monetary or economic benefit you believe you’ll receive. Once the virus is allowed out of containment, it will spread in an uncontrolled manner every single time.
The second implication should also be clear. There is no path to any sort of herd immunity absent a vaccine. The paper provides the formula for herd immunity. In its simplest form, it’s just 1-1/R0. For R0=5.7, that requires 82% of the population to be immune. And that’s moving up into the 95% required for herd immunity to measles, something we were only able to achieve through a vaccine.
And, of course, the talk of immunity revolves around the naive assumption that exposure to the virus results in some sort of natural, lifetime immunity to it. There is nothing that indicates that’s a reasonable or likely assumption and quite a bit of early evidence that it is wrong. A lot of people with light exposures don’t have the right sort of antibody cells that encode immune system memory. But that’s true even of some who were seriously ill. They are finding that others do have the right sort of antibody but there isn’t yet any data that indicates the degree of natural immunity or how long it lasts. It’s good there appears to be a mechanism that produces the antibodies with memory. If there weren’t, it’s my understanding that a vaccine wouldn’t be possible. But it does not appear to operate at all evenly across the human population as a result of infection and recovery. A well-designed vaccine would have a much higher and more consistent rate of effectiveness. The early data also present a clear warning: If you’ve had COVID-19 and recovered, DO NOT assume you are immune! Wait until tests and supporting data clearly support the likelihood that you personally are immune.
So what do we need to do? The answer is not a mystery. It’s perfectly straightforward. We need to do what most other countries are already doing or preparing to do. First we must suppress the initial outbreak. That means a full lockdown until virus levels fall to whatever our capacity in an area to perform the second step might be. (That will not be consistent around the country.) We have not yet suppressed the initial outbreak anywhere in the United States. We are still at step one across the entire nation.
The second step is containment: test, trace, and isolate (TTI). It requires extremely widespread and easily available testing with reasonably rapid results. Some places, like nursing homes, will require multiple rounds of 100% testing of staff and residents. Health care workes require regular universal testing. Everyone working in close, frequent contact with others must be tested regularly. Test. Test. Test. As much as possible of the entire population in a region must be tested over time and continually retested. Every positive must be isolated until they are recovered and all their contacts who might possibly also have been infected must be traced, tested, and isolated as well.
If TTI fails in an area and containment is broken, the virus will begin to spread again in an uncontrolled manner. Once that happens and testing detects it, the area must immediately go back into full lockdown mode until the new outbreak is once again contained. However, even with full TTI in place, it is not likely that all restrictions will be able to be relaxed anywhere.
That cycle will continue until a vaccine is discovered and through vaccination herd immunity is achieved without mass death and suffering. That is and has always been the only moral choice and if this virus is as contagious as it appears to be, it’s also the only practical choice.
Those who do not follow those steps will see their hospitals overrun and their death rates skyrocket precisely as we saw in Italy, Spain, and New York. It’s not a question of if; it’s a question of when. And right now, the ‘when‘ is only weeks away for many parts of this country.