“On top of all that, every person’s immune system is unique, making immune systems harder to generalize, harder to understand, and harder to treat when they go wrong. Moreover, the immune system doesn’t just deal with germs. It has to respond to toxins, drugs, cancers, foreign objects, and even your own state of mind. If you are stressed or exhausted, you are much more likely to suffer an infection, for instance. Bryson, Bill. The Body (p. 200). Knopf Doubleday Publishing Group. Kindle Edition. ”
