How Does the Immune System Work?

Part-2 by: Jonathan Vellinga, M.D.


Most of us probably do not think much about our immune system, unless we are fighting an illness or in the midst of a pandemic. One good thing to come from the COVID-19 pandemic is a greater awareness of the importance of maintaining a healthy immune system and taking measures to prevent the spread of germs.


Since overall health is vital to a strong immune system, we recently explained the importance of maintaining the 5 Pillars of Health. We discussed the importance of each pillar: sleep, exercise or activity, nutrition, stress management, and relational or emotional health. We also reviewed specific things you can do to strengthen each one. You can read all about it in this post.


In addition to the five pillars of health, there are five goals we can target to strengthen specific components of the immune system. In order to understand the significance of each goal, it helps to have a basic understanding of how the immune system works. So, here is a very simple overview of how a healthy immune system should work and goals to strengthen it.


Immune System

Reasons We Become Ill


There are two major factors in your likelihood of becoming ill after exposure to a pathogen. The first is your level of health and the strength of your immune system. This makes sense if you consider that immune-compromised, elderly, and very young people are usually most at risk during an outbreak.


The second factor is the dose you are exposed to. Simply being in the same room as an ill family member brings a lower risk than if your child repeatedly sneezes or coughs right in your face. This is why health care workers can become seriously ill and even die during a viral outbreak. They are exposed to the virus in such high quantities that their normally healthy immune system becomes overwhelmed. Add to that a lack of sleep and high stress levels when dealing with an epidemic and it becomes surprising that more medical personnel do not become ill.


Strengthening the Immune System


As mentioned earlier, there are five areas of the immune system that we can improve through our actions. When these goals are met your chance of falling seriously ill can be greatly reduced.


These goals are:


  1. Enhance barrier integrity: improve the lining of our respiratory tract, gut, blood-brain barrier, and skin.

  2. Increase production of antimicrobial peptides: small amino acid linked chains that fight against infections.

  3. Promote phagocytosis: a process when white blood cells, such as macrophages, are better able to recognize and consume infected cells, microbes and/or viral capsids.

  4. Decrease inflammation and restore redox balance: lots of oxygen free radicals lead to immune imbalance and increased inflammatory products.

  5. Activate intracellular defense pathways: a process that allows cells that take on bacteria to kill them before they can replicate or cause damage (Nrf2 and SIRT1 activation.)


Before we discuss these ways to implement these goals, it helps to have a basic understanding of how the immune system works. So, here is a very simple overview of how a healthy immune system should work.