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Edward Jenner
In 1796, a young English
country doctor called Edward Jenner first tested out his new vaccine for
smallpox, a horrible disease that had killed millions of people over the
centuries.
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Medicine hadn't really been
used to prevent people catching diseases before. Medicine was usually used
after someone had got an illness to try to cure it. However, when Jenner was a
medical student, he noticed that women who milked cows often caught a mild
disease that was common in cows, called cowpox. When cows got this, they got
blisters on their skin. The women who caught it also had a few mild symptoms,
but nothing very serious or life-threatening. The really exciting thing
that Jenner realised was that the women who caught cowpox did not get smallpox,
even when they had been in contact with someone who had the disease. He didn't
know why this was but he decided to conduct an experiment.
On 14thMay 1796, Jenner took fluid from a cowpox blister and scratched it into the skin of James Phipps, an eight-year-old boy. A single blister rose up on the spot, but James soon recovered. On 1st July, Jenner inoculated the boy again, this time with liquid from a smallpox blister. No disease developed. The vaccine was a success!
The reason that the little boy was protected from smallpox was that the microbes (germs) which cause smallpox are very similar to the microbes that cause cowpox. After he had been infected with cowpox, James' immune system recognized cowpox germs and knew how to fight them. When he was infected with smallpox, his immune system knew how to get rid of it, because it was so similar to the cowpox germ. His immune system would have quickly destroyed any smallpox microbes before they had a chance to take hold in James' body and multiply. Therefore, the smallpox did not make James ill.
Doctors all over Europe soon adopted Jenner's new method. It led to a huge drop in the number of people getting smallpox.
In the 19th and 20th centuries, scientists following Jenner's example developed new vaccines to fight numerous, deadly diseases, including polio, whooping cough, measles, tetanus, yellow fever, typhus, and hepatitis B and many others. Smallpox has now been virtually eradicated worldwide because of international vaccine programs.
Glossary
eradicate - to completely get rid of something such as a disease
immune system - the organisation of white blood cells that protects the body against disease and fights illness and infection
infect - to give someone a disease
inoculate - to introduce a germ, usually a weak type, into someone's body in order to protect them from it later
multiply - to increase greatly in number
symptom - a physical condition which shows that you have a particular illness
vaccine - the substance which contains the germ that causes a disease and is used to protect people from that disease
On 14thMay 1796, Jenner took fluid from a cowpox blister and scratched it into the skin of James Phipps, an eight-year-old boy. A single blister rose up on the spot, but James soon recovered. On 1st July, Jenner inoculated the boy again, this time with liquid from a smallpox blister. No disease developed. The vaccine was a success!
The reason that the little boy was protected from smallpox was that the microbes (germs) which cause smallpox are very similar to the microbes that cause cowpox. After he had been infected with cowpox, James' immune system recognized cowpox germs and knew how to fight them. When he was infected with smallpox, his immune system knew how to get rid of it, because it was so similar to the cowpox germ. His immune system would have quickly destroyed any smallpox microbes before they had a chance to take hold in James' body and multiply. Therefore, the smallpox did not make James ill.
Doctors all over Europe soon adopted Jenner's new method. It led to a huge drop in the number of people getting smallpox.
In the 19th and 20th centuries, scientists following Jenner's example developed new vaccines to fight numerous, deadly diseases, including polio, whooping cough, measles, tetanus, yellow fever, typhus, and hepatitis B and many others. Smallpox has now been virtually eradicated worldwide because of international vaccine programs.
Glossary
eradicate - to completely get rid of something such as a disease
immune system - the organisation of white blood cells that protects the body against disease and fights illness and infection
infect - to give someone a disease
inoculate - to introduce a germ, usually a weak type, into someone's body in order to protect them from it later
multiply - to increase greatly in number
symptom - a physical condition which shows that you have a particular illness
vaccine - the substance which contains the germ that causes a disease and is used to protect people from that disease
