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Vaccination
administration of a vaccine to protect against disease / From Wikipedia, the free encyclopedia
A vaccination is a treatment which makes the body stronger against an infection.
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The body fights infections using the immune system, which is made up of millions upon millions of cells including T cells and B cells. An important part of the adaptive immune system is that it is much stronger when fighting a disease that it has already fought against before. Vaccination involves showing the immune system something which looks very similar to a particular virus or bacteria, which helps the immune system be stronger when it is fighting against the real infection.
The World Health Organisation estimates that vaccines save 4-5 million lives per year.[1]