Immunity is defined as the state of resistance or in susceptibility to disease caused by particular microorganisms or their toxic products.
TYPES OF IMMUNE SYSTEM
Innate immunity is the first line of defense against pathogens and response is more general and non-specific.
Innate immunity includes the external barriers of our body — the first line of defense against pathogens — such as the skin and mucous membranes of the throat and gut.
Adaptive (acquired) immunity
Immunity which is developed later in life after microbial infection in host is called as Acquired or developed immunity. For example, If an individual is infected with chicken pox virus, he/she become resistant to same virus in later life.
Components of acquired immunity such as Antibodies and T- cells are specific to particular microorganism. Therefore acquired immunity is also known as Specific immunity.
Types of acquired immunity:
Antibodies that develop in a person's own immune system after the body is exposed to an antigen through a disease It is slow and takes time in the formation of antibodies. This type of immunity lasts for a long time.
This type of immunity is “borrowed” from another source, It is not long lasting. For instance, a baby receives antibodies from the mother through the placenta before birth and in breast milk following birth. This passive immunity protects the baby from some infections during the early years of their life.