What are vaccines, how do they work and why are people sceptical?
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How was vaccination discovered?
Before vaccines existed, the world was a far more dangerous place, with millions dying each year to now preventable illnesses.
The Chinese were the first to discover an early form of vaccination in the 10th Century.
Eight centuries later, British doctor Edward Jenner noticed how milkmaids caught mild cowpox, but rarely went on to contract the deadly smallpox.
In 1796 Jenner carried out an experiment on eight-year-old James Phipps.
The doctor inserted pus from a cowpox wound into the boy, who soon developed symptoms.
Once Phipps had recovered, Jenner inserted smallpox into the boy but he remained healthy. The cowpox had made him immune.
In 1798, the results were published and the word vaccine - from the Latin 'vacca' for cow - was coined.
https://www.bbc.com/news/world-48186856