Vaccinations:

Vaccines are when a dead or weakened sample of a disease is put inside your body.
Once you have had a vaccination, the white blood cells in your body make antibodies to kill the disease.
Now that the antibodies for this disease have been made, they will stay in your body and if you ever catch that disease again, it will not affect you because the antibodies will get rid of it.
This means you are immune to this disease.

How vaccines were discovered:

Edward Jenner, who was a doctor, though it was strange that the milkmaids caught Cowpox from the cows they were milking, but then never caught Smallpox, which was a deadly disease.
He decided to put a small sample of Cowpox into a young boy, in order to find whether it would make him immune to Smallpox.
The boy became very ill with Cowpox, but eventually recovered.
Once the boy was better, Jenner gave him a sample of Smallpox, and the boy did not catch the disease.
This was how vaccines were found.

	Created by Ellen Billingham over 11 years ago

GCSE Biology (Movement and Health) Note on Movement and Health, created by Ellen Billingham on 12/05/2013.