Invisible forms of life, called germs, are present in the air, soil, food and also in water. Many of them cause diseases or infections. The human body has an ability to fight the attack of germs naturally. This ability to fight is called immunity. Immunity can be categorised into innate immunity and acquired immunity. Innate immunity is the immunity with which we were born. Acquired immunity develops when the body gets exposed to various antigens (foreign substances); and eventually defense against that specific antigen is built, for example, vaccination for typhoid and diphtheria.
What is Immunity?
