Today's children have barely even heard of the disease, but when I was a kid, it was every parent's greatest fear for their child - that crippling, sometimes deadly, disease called polio. I can distinctly remember how my mother didn't even want me to be in big crowds because of how polio seemed to spread so quickly. But then along came the vaccine. We all got our shots and we were immune to polio. Since then, there are a lot more shots like that for everything from smallpox, to tetanus, to the flu. And they all work basically on the same principle: in essence, you get a little of the virus injected into your system so that your body will build up an immunity to what could otherwise cripple you or kill you. That kind of immunization can save your life. But, on the other hand, immunization can be really dangerous - even deadly.
A UNC professor is driving along the road when he sees a sign on a plot of land that reads "40 acres for sale" and lists a phone number and in big bold letters the words "WILL DIVIDE". The man has been considering buying a bit of land for investment purposes. He calls the number and when a lady picks up, he asks her, "Is Mr. Divide in?"