Pustules on the hand of a person with cowpox. The illustration is from 'An Inquiry into the Causes and Effects of the Variole Vaccine' by Edward Jenner, an English physician (1749-1823). Jenner coined the word vaccination to describe his use of cowpox inoculation to obtain immunity to smallpox. Stories from his native Gloucestershire suggested that dairy hands who had contracted the milder cowpox did not contract the deadlier small pox. Jenner experimented on a small boy by inocul- ating him with fluid obtained from the blister of a patient with cowpox. He later inoculated him with smallpox. The boy survived & did not contract smallpox. This practice quickly spread.