You live in a world of germs and you’re at war. Your body’s constant, warm environment, rich in nutrients, is an ideal home, where tiny organisms can thrive. Their aim is to get in. Your body’s job is to keep them out. Through advances in cancer research, scientists now believe more than 100 million immune cells exist. For every virus or bacterium, there seems to be an immune cell specifically designed to hunt down and destroy it. But what happens when you are born without this ability?
The immune system is a network of cells and organs that work together to defend the body against attacks by foreign “invaders”. These are primarily germs-tiny, infection-causing organisms such as bacteria and viruses, as well as parasites and fungi. Because the human body provides an ideal environment for many germs, or microbes, they try to break in. It is the immune system’s job to keep them out or, failing at that, to seek them out and destroy them. Without the blood cells needed to perform this function, your body is susceptible to any disease or infection. Some of the problems associated with an improperly functioning immune system are arthritis, asthma, allergies, psoriasis, lupus, cancer, chronic fatigue syndrome, and a tendency to always be fighting some infection.
Infections are the most common cause of human disease. They range from the common cold to debilitating conditions like chronic hepatitis to life-threatening diseases such as AIDS. Microbes attempting to get into the body must first move past the body’s external armor. The skin and the membranes lining the body’s gateways not only pose a physical barrier, they are also rich in scavenger cells and IgA antibodies. In normal humans, microbes that cross the nonspecific barriers must then confront specific weapons tailored just for them. Specific weapons, which include both antibodies and cells, are equipped and with singular receptor structures that allow them to recognize and interact with their designated targets. Without these barriers to block out unwanted foreign cells, your body has no way to stop the infection from spreading.
Infants, who are born with weak immune responses, are protected for the first few months of life by antibodies they received from their mothers before birth. Babies who are nursed can also receive some antibodies from breast milk; these help to protect the digestive tract. However, babies with no immune system at birth must spend a great deal of their life, if not their entire life, building up enough of an immune system to leave a protected environment and return to the outside world where infections can be spread through the wind.