Question

the principle of immunisation

Answer 1

immunisation, is the process by which an individual's immune system becomes fortified against an agent (known as the immunogen). ... The most important elements of the immune system that are improved by immunization are the T cells, B cells, and the antibodies B cells produce.

Answer 2

For immunisation, weak virus or bacteria is injected in the body of the person(vaccine), being weak it does not causes any harm but to prevent the body from the disease, our immune system releases a no. of anti-bodies. When next time that particular disease whose vaccine was given earlier contracts our body, the immune system recognises the disease easily and immediately releases the earlier made anti-bodies and therefore body gets immuned to that disease.
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