It’s a Journey – The Immune System

Imagine you have a $3M house smack in the middle of a dangerous part of town. Bad stuff goes on outside your perimeter. A tall concrete fence topped with barbwire surrounds your property; strategically placed cameras provide 360 degree views of the periphery. The gate can only be opened electronically.

All of the open yard area is equipped with motion detectors. The house itself is protected by a security system that sounds an impressive alarm when anyone or anything attempts to enter a door or a window.

A 24 hour security detail is housed on your roof. They maintain visual patrol plus monitor the cameras and motion alarms. At any sign of trouble the guards release several mean Doberman Pinschers and prepare, if necessary, to call in the national guard.

You live happily within the confines of your house, confident you are protected from bad stuff happening outside.

The innate immune system.

Consider what I have just described as your “innate” immune system. That is the first of two parts of your complete immune system.

The innate system is on patrol at all times, getting signals from your various cells in your body when something shows up that doesn’t belong. Just like the Doberman’s mentioned above, the innate system doesn’t know exactly who the invader is but it responds immediately to attack, doing its best to kill anything dangerous before it gets into your cells and starts an infection.

The adaptive immune system

The innate system also alerts the adaptive immune system to gear up in case the innate response isn’t enough.

The adapative system consists of T-cells and B-cells, both of which take a few days to be ready. Why so long?

All cells are made of protein. T-cells and B-cells are looking for the proteins in invaders which are different from human proteins. The presence of foreign proteins tell the immune system which cells to attack. There are an infinite number of possibilities and identifying the right ones will take some time. Their job is to fight an active infection that the innate system fails to stop.

Invaders could be a lot of things that don’t belong. Some could be one of 208 viruses, 538 bacteria, 317 fungi, 287 worms, and 57 parasites. At least that was the number the last time I looked.

T-cells and B-cells are being continuously created in the bone marrow and dumped into circulation. whether there is an invader or not. When they are signaled to activate by the innate system, they begin looking for mismatched proteins.

I won’t explain how the adaptive immune system works in depth because it would take too long and be too complicated. Should you want to know more, the website version of this article contains links providing detail.

Suffice to say that, once ready, the T-cells are moving in force through your blood and lymph system checking every one of your cells for mismatches and taking steps to destroy infected cells. There are several different kind of T-cells that employ different strategies.

Once matured, the B-cells, on the other hand, arrive with antibodies attached. This again is a need to find the mismatched protein that the antibody can attach to.

Once the B-cell encounters an invader that matches its antibody, it divides and replicates into two forms. One type becomes a memory cell, the other circulates in the body secreting the antibodies. The killing goes on.

Replicated memory cells are stored in bone marrow for future use. This means should the invader, whatever it is, show up again on another day, the response to that invader can happen much faster. Vaccines are antibodies “on ready”.

When the immune system isn’t tied up responding to invaders that might kill you it also repairs wounds, disposes of dead cells, and removes abnormal cells (such as those that can become cancer). Abnormal cells don’t belong either.

Why the Immune System might not work right

I have described what will happen in a healthy person. On occasion some portion oa a person’s immune system can be faulty due to genetics. Plus some invaders are worse than others.

For example, the HIV virus typically infects T-cells themselves and they mutate at warp speed. That helps explain why a vaccine has not been identified and extraordinary efforts were required identifying drugs that will stop the virus from replicating.

On occasion the system seems to get confused, thinking that some human protein (called self) is foreign (not self) and attacks. This results in an autoimmune condition.

That brings us to the “underlying conditions” (including autoimmune conditions) that challenge the immune system all on their own. These belong to unhealthy people and are frequently present in older folks.

Finally, nutritional requirements may not be met. Every single cell in your body, including immune cells, has a requirement for the right vitamins and minerals, proteins and healthy fats. The typical American diet fails rather badly in providing for these requirements. “Underlying conditions” most often occur for the same reason.

When it comes to fighting off infection, being sick is not a good thing. Being old and sick is worse still.


Covid-19 is a new virus not seen before. None the less so far we know that the innate immune system seems to handle Covid-19 for a large percentage of younger people, regardless of the variant.. We know that 90% of people hospitalized will not be vaccinated. We know that majority of those who die are unvaccinated folks with underlying health conditions. We also know that there have been miraculous survivals in old folks without underlying health conditions. Health seems to be the key.

Pat Smith is the author of “It’s All about the Food,” a book that guides nutritious food choices as the way to avoid illness and maintain a healthy weight. Proceeds from her book benefit the Montgomery County Food Pantry. Her website is She can be contacted at, 501-605-3902. Her Facebook page is