In the prior piece, it was suggested that the antibodies were not the major player in this. So what is? Not likely surprising to you, using the analogy of the house broken into, the most important are the barriers that are keeping the little buggers out in the first place. After all, if they can be prevented from getting into the body, there can be no infection.
How do they get in? Most of the bacteria, viruses, etc., come through the eyes, mouth, nose, other openings like urethra, vagina. They can also be swallowed and enter through the lining of the intestinal tract.
What about the skin? The skin is pretty tough and getting past the skin is only possible if it is cut or punctured in some way. Granted there are a few organisms, like some fungi, that just start growing on the skin, but these are few. You can assume that viruses and bacteria come in the other way.
It actually turns out that the skin is a small area comparatively. For the human being, the skin area is about two square meters while the mucous membranes of the other entries — the openings mentioned above and the mucous membranes of the breathing and digestive systems — are about 400 square meters, about the size of two tennis courts. So this is where most of the attention is given by the immune system.
The cells that sit in these tissues, that I am calling the Guardians (because I like that word), are also called macrophages. This name comes from “macro” meaning “large” and “phage” meaning “to eat.” They are indeed large cells and eat about anything. They will clean up any mess they run into. They can detect invading organisms by sensing some molecules on the surface of the germ that are not normally found in the body. They make their way to the bacteria (or whatever) and basically eat it. This eating process is taking in the virus, bacteria, fungus, and digesting it inside the cell with chemicals already stored in the cell.
This is a pretty good method, isn’t it? All these guys are sitting there 24 hours a day, watching, watching, for anything suspicious. This primary defense method has been around a long time — millions if not billions of years if we factor in early forms of life.
WHERE DO THEY COME FROM?
In humans & other animals these Guardians originate in the bone marrow, the same place that red blood cells are made. They grow from the same cells that make red blood cells, as well as other immune cell types we will get into later. To give you some idea of how active the bone marrow is in this, it has been determined that more than two million red blood cells are manufactured each second to replace what is lost, this being the normal process of a healthy person. I don’t know about you but the numbers are so great I can hardly get my head around it.
These Guardian cells are produced in the bone marrow, move out into the blood on their way to their “stations.” While circulating in the blood, they are called “monocytes” and there are two billion of them in your blood all the time. After about three days they will have moved through the blood system to their stations in the tissues mentioned above. There they sit and wait, with great patience. Are we not lucky?
These Guardian cells are the first and primary defense. There are other levels of this primary defense (what is called the Innate system which we will get into) but the Guardians are the front line, the most important in terms of keeping anything out.
This defense system works sufficiently almost all the time if the person or animal is healthy. Realize, if you can, perhaps visualizing, that any virus that comes in through the mouth or nose and lands on a mucous membrane, if it is eaten by the Guardian cells that is the end of the story. There will be no infection.
Realize too that this happens without the presence of any antibodies. Not only are there no antibodies needed but there will not necessarily be any produced from this encounter. There is no need for that. It is possible there could be antibodies coming about in those encountering large numbers of the virus, or having repetitive exposures. However, a one-time event will not usually be seen as that significant.
Does it impress you to say that 99% of all animals do just fine with just this mechanism we are discussing here? I mean this is the entirety of what they have, no additional antibody or immune cell function like we do. Surely you can see how efficient it is.
THE CURRENT EPIDEMIC
Let us translate what we are discussing here into the issue facing those studying the present epidemic. Those working on this would like to be able to estimate how contagious the virus is, how many are infected, what the death rate is, etc. Can you see that the people who encounter the virus, and have it for lunch, may not show any evidence of that? They will not be sick, they will not be passing on the virus to others, they will not be making antibodies. Basically you cannot identify them.
To know that a person has been exposed, the evidence necessary is either the signs of infection or the presence of antibodies. Granted it is possible to produce antibodies without showing symptoms (more on that later), but it is also important to know, as said above, that exposure does not always result in this.
Do you see the difficulty? It is very tough to have an accurate estimation of exposure. For example, if the actuality is that 80% of the population is exposed (including those as described above that do not show any evidence of it) and if we were to know that percentage, and then calculate that the death rate is 1%, we would have a reasonably accurate assessment of the how often the virus causes death.
But a different value will come up if we limit the exposure to those developing antibodies — these being the ones in which the virus got through the door and did some spreading around. If we measure that 20% of the population has antibodies and assume that this is the total of those exposed, the apparent death rate is now said to be 4%. This is not accurate, is it?
Another way to put this is that if the majority of the population is very healthy and basically throws off the virus without developing immunity, then that is a reflection of low susceptibility, a reflection of how healthy the population is. On the other hand, if the population is not very healthy and a significant percentage show antibody production because they could not withstand it, why would we then turn and blame the virus, saying “it is very contagious, very dangerous”?
Tricky business. Well, that is how life is — very clever and not usually as simple as we think.
Can you see, from what we are discussing as the primary defense mechanism, how important it is that we are healthy? Our bodies are constantly making these cells, millions each day, and also reproducing the tissues of the mucous membranes. If anything interferes with this, we become susceptible.
What would interfere? Poor nutrition — eating food that contains toxic chemicals — is a big one. As an example, did you know that a recent report found that 98% of Americans have Roundup in their bodies?
There is also lifestyle, how much fresh air and sunlight we experience, how much exposure to radiation (many concerned about 5G coming in), taking drugs that interfere with the immune system like steroids, anti-inflammatories. This a big topic in itself, let us just say here that it would be very effective and intelligent to emphasize maximum health as the best defense. Rather than having everyone wearing masks, maybe it would make more sense to reduce air pollution?
There is more to the immune system. There is all the drama that happens if the virus gets past the Guardians. That is what happens in those that actually get sick. The immune system has many more defenses that we can explore as we go along.
[ Reference: For much of this information I am drawing on a very good book by Lauren Sompayrac, entitled “How the Immune System Works.” You might want to study it if you have that interest.]