The single most important achievement in public health in the twentieth century has been almost complete eradication of many communicable diseases. Through global initiatives of providing universal vaccinations, two major and devastating diseases, smallpox and polio, have been almost completely eradicated. What makes vaccination so spectacularly successful is that it is one of the most cost effective means of improving overall health. For no more than a dollar or two per person or less, it is possible to completely eliminate devastating diseases from our planet, benefiting all people in the world. The triumph over polio -- which left its victims paralyzed -- is particularly impressive.