Question

What is the definition of disease? What is immunisation?

Answer 1

any undesirable change in the body is referred as disease.
immunisation refers to injecting of weakened or dead microbes to make antibodies in your body.

Answer 2

Abnormal condition of a part, organ, or system of an organism is called disease.

Immunisation : It is the process of human body to make immune or resistant to an infection disease. Sometimes get into vaccine.