Entry #10: Immunoglobulins and You: Understanding Your Immune System

The human immune system is one of natures most ingenious designs. This system allows humans to fight back foreign intrusions within the body. Microscopic organisms are everywhere and many exist normally on skin and in mucous membranes and even your own digestive track is littered with little bugs. So, how does are body keep this system in check? What makes up the human immune system?


The human immune system is made up of several different parts. Most notably these are White Blood Cells, Immunoglobulins, and other chemical/protein substances that attack or damage other cells. To fully discuss the entire immune system would quite literally take maybe one to two semesters of upper division college coursework. No worries though, I will keep it short and simple and we will just look at one of the most important immune factors. These are called immunoglobulins. Immunoglobulins are just a fancy way of saying antibodies. The illustration at the top left describes the different parts of an immunoglobulin. The three really important parts are the antigen binding sites (Ag), the Fab zone, and the Fc chain.

Take a look at the illustration to the left and directly below. These immunoglobulins look different. That's because there are 5 distinct types of immunoglobulins. These are IgG, IgA, IgM, IgE and IgD. The most common type is IgG which accounts for nearly 80% of the body's total immunoglobulins. Each type of Immunoglobulin has a role and often times they are found in different areas of the body. Take a look at the chart below to see where and what these different types do. The reason its so important to talk about your immune system is so that you understand the roles vaccines play and how herd immunity protects large groups of people. Most vaccines contain an inactivated virus or bacteria. This usually means that only the antigens, that line the surface of these micro-organisms, are present. When injected into your body the first thing the immune system does is think. Oh my gosh what is this? This doesn't belong! Then the body has to think about whether it has encountered this type of antigen before. Most likely it hasn't or it simply doesn't remember if it did. In these cases, the immune system responds by sending large amounts of IgM in an attempt to find and antibody that will work. Once the body discovers a good defense the White Blood Cells start to produce IgG. These IgG form the an immune systems long-term defenses. They are specialized in a certain antigen.

In vaccines, the body learns to identify the antigens that were injected and then to produce an immune response to defend against them. This production of IgG attributes to future immune responses. So if you were vaccinated against polio, your body no longer has to go through the IgM learning phase. It would recognize the polio virus and the already circulating IgG (learned immunity) would respond to a new introduction of the virus very quickly, which increases the odds for a favorable outcome.

So when a group of people in society get vaccinated it makes it incredibly hard for a virus to jump through and infect a large number of people. By isolating the illness it can stop the spread of it and eventually reduce or eliminate it. This is why certain diseases have become almost completely extinct. Smallpox for example, was reduced this way.

Please Please Please. Think about stopping by your local pharmacy to learn about getting vaccinated. Also think about exploring more into the immune system. Take science courses and discover new things.