Measles and TB evolved from diseases of our cattle, influenza from a disease of pigs, and smallpox possibly from a disease of camels. The Americas had very few native domesticated animal species from which humans could acquire such diseases.
The thing is I think vaccines are one of the greatest medical breakthroughs that we have. I'm a big fan and a great fan of the history of the development of the smallpox vaccine, for example.
Infectious diseases introduced with Europeans, like smallpox and measles, spread from one Indian tribe to another, far in advance of Europeans themselves, and killed an estimated 95% of the New World's Indian population.
It is a remarkable fact that smallpox, a scourge for thousands of years, has now vanished from the earth, except for two tiny vials, one locked in a highly secure facility at the Centers for Disease Control, in Atlanta, and another stored in a similarly secure vault in Siberia.
The CIA now assesses that four nations - Iraq, North Korea, Russia and, to the surprise of some specialists, France - have undeclared samples of the smallpox virus.
While eliminating smallpox and curtailing cholera added decades of life to vast populations, cures for the chronic diseases of old age cannot have the same effect on life expectancy. A cure for cancer would be miraculous and welcome, but it would lead to only a three-year increase in life expectancy at birth.
I hope that some day the practice of producing cowpox in human beings will spread over the world - when that day comes, there will be no more smallpox.
In 1967, the world health community launched a global effort to eradicate smallpox. It took a coordinated, worldwide effort, required the commitment of every government, and cost $130 million dollars. By 1977, smallpox had disappeared.
Smallpox, which spreads by respiration and kills roughly one in three of those infected, took hundreds of millions of lives during a recorded history dating to Pharaonic Egypt. The last case was in 1978, and the disease was declared eradicated on May 8, 1980.
Oh, if I had been loved at the age of seventeen, what an idiot I would be today. Happiness is like smallpox: if you catch it too soon, it can completely ruin your constitution.