Herd immunity, or what I refer to as population immunity because I would like to believe we aren’t animals, is the notion that at some point enough of a population will have immunity to a pathogen so that transmission stops or occurs at a very low level. This immunity, which is referred to as adaptive immunity, might arise from the response of the immune system to an infection, or in modern times it might occur through vaccination which prompts an immune response to some or all of the pathogen”s components. In the early part of the CV-19 epidemic our woefully inept public health experts were claiming that population immunity might occur at a level of 70% to 80% of the population having been infected.
A new study of blood donors in the Journal of the American Medical Association estimates that by December of 2021 the prevalence of CV-19 antibodies in the population was 95%. Despite this, we have since then had a massive Omicron wave, which continues through today. (JAMA Article) It should now be apparent to everyone, including those incompetent public health officials, that there is no such thing as population immunity to CV-19 infection. Everyone is going to be repeatedly exposed and likely infected, just as we are with seasonal coronaviruses and multiple other pathogens. Why does this happen? It is actually pretty obvious.
We are dealing with a respiratory virus. We all breathe all the time. We have a very poor understanding of, and seriously underestimate, the ability of these viruses to persist in the environment and travel over extended distances. They also have multiple animal reservoirs. They mutate frequently due to the number of replication events. Constant exposure is likely. In my epidemic presentation, I always talk about the micro-level and the macro-level. At the micro-level, exposure in a person with adaptive immunity does not mean that there will be no infection. Adaptive immunity, whether derived from infection or vaccination, primes the immune system to recognize a particular pathogen and to react rapidly to exposure. It does not prevent exposure. If you breathe, you can be exposed. And a person can become “infected”, meaning the virus manages to get inside a cell and begin replicating, any time they are exposed. And because most CV-19 infections are incredibly mild, our immune system’s are smart enough to not go overboard in creating a defense. They aren’t going to waste limited resources defending against a pathogen that isn’t life-threatening.
A person with adaptive immunity, however, should have a good response to each exposure resulting in an infection. Antibodies, T cells and other immune components should quickly clear the infection and limit serious disease. And we see that at this point in the epidemic most infections are at worst a cold. The level of hospitalizations and deaths is grossly exaggerated by calling anyone with a positive test any time prior to their hospitalization or death a CV-19 event. The current circulating CV-19 variants are very mild, akin to the other seasonal coronavirus. I believe there is every reason to think this is the fifth common circulating coronavirus. And the other four probably went through the same process of being a substantial epidemic until humans developed enough adaptive immunity to limit serious disease.
So we are not going to ever have population immunity in the classic sense–CV-19 will be with us, and we already have adapted to it. We should be pleased with that. Enough of us have some form of immunity that we are unlikely to see significant amounts of serious disease. And all those re-exposures will keep our immune system well-primed. So let’s stop with the crazy testing and reporting and promoting endless doses of vaccine.