The first "vaccine"-- before the word "vaccine" was invented was inoculation for smallpox, using actual pus from smallpox pustules. The practice, by varying methods, seems to have been in use well before western medicine took notice of it. Knowledge of the procedure spread to western medical men from several sources during the early 18th century, including China and Africa.
The most influential source was reports of the practice in the Ottoman Empire. The most famous conveyor of the knowledge was Lady Mary Wortley Montagu, whose husband was British ambassador to the Sultan for several years in the 1710s. She had her children inoculated. (Shown here with her son and in "Turkish" dress.)
Lady Mary's reports and encouragement helped lead to a series of experiments in London with the procedure in the 1720s. One of the most important involved the inoculation of the children of Princess Caroline of Anspach, wife of the future George II.
The princess was no doubt influenced by the death from smallpox of Queen Mary, wife of William III, in 1694 (William and Mary).
The success of these experiments, combined with news of similar successes in America promoted by Rev. Cotton Mather of Massachusetts and others, led to the practice becoming common in the British Empire by the mid-18th century. (Image: Cotton Mather)
The procedure was not without its dangers. About one percent of those inoculated died. In contrast, natural smallpox had fatality rates often exceeding 20 per cent. After 1800, inoculation with actual smallpox was gradually replaced by the less dangerous method of using "cowpox" matter to immunize against the disease.
(This romanticized image shows Edward Jenner inoculating James Phipps with cowpox matter from pustules of Sarah Neames, milkmaid, on far right wrapping her hand)
This was the first method to be called "vaccination" a word derived from "vacca" -- Latin for "cow." The spread of vaccination in the 19th and 20th centuries led to the global eradication of smallpox by 1979, the first and only disease to be eliminated by human action.
(See my earlier post on vaccination for more information on that story.)