You might be missing out on some immune-system superpowers that are yours for the asking at your local pharmacy. Besides protecting yourself—who wants chicken pox and tetanus?—staying up-to-date on shots helps to keep dangerous germs out of circulation and away from others.
Tetanus, a dreaded bacterial infection, used to be a terror of the world. Frequently fatal, its first sign was the stiffening of the jaw that rendered the sufferer mute. But how does a bacterium lock a person's jaw shut, anyway?