Inoculation

Inoculation (also known as variolation) is an historical method of making people immune to smallpox. Unlike a vaccine, inoculation uses infected material (for example scabs) from an infected patient. The benefit of inoculation is it gives the individual a less dangerous type of the virus. Another benefit of inoculation is the fact it has a death rate of 0.5% - 2% (as opposed to the 35% death rate of smallpox). Inoculation was eventually replaced after Edward Jenner discovered a vaccine against smallpox. 
Historical uses.
China.
China may have used inoculation in the 10th century. The Emperor of China at the time lost his eldest son to smallpox. He wanted a way to help prevent smallpox from killing any more members of his family. He summoned many people from throughout the empire to attempt to find a cure to smallpox. A man carried out inoculation to Immunise his family. However, the source of the story was supposedly written 100's of years after the event. 
Inoculation was not widely used in China until the 'Longqing Emperor' in the 16th century. This was written by Yu Tianchi. Inoculation using the most deadly strain of the virus was banned from use in China to prevent high death rates. Inoculation is documented to have been used in India in the 18th century. It may have been used earlier than that, but there is no evidence to prove this. 
Importation to Europe.
The practice of Inoculation was first used in England after an ambassador's wife witnessed it in Constantinople. Her name was Lady Mary Wortley Montague and she was impressed by the benefits. She had lost her son, and bore scars of the virus herself. When an epidemic of smallpox occurred in England in 1721, she ordered that her daughter be inoculated. Many people visited her daughter, and were impressed at the results of inoculation. Eventually, inoculation was tested in Newgate Prison. This was before the members of the royal family were inoculated. After the success in England, many European countries began to use inoculation against smallpox.
Decline in Use.
In 1796 Edward Jenner discovered a vaccine against smallpox which had a very low death rate. It was also more effective. Inoculation began to be replaced by this new vaccine, and was eventually outlawed in England in 1840. France banned Inoculation in 1762 due to the death rates associated with it.