Question

Immunity When we say that we are immune to a specific infectious agent, what are we talking about? How many different types of immunity are there? Tell us a bit about each and how it works.

Answer 1

Ans . When we say that we are immune to a specific infectious agent it means we are talking about specific immunity which is also known as adaptive immunity or acquired immunity. This type of immunity is capable of recognizing and selectively eliminating specific foreign antigens. it does not come into play until there is an antigenic challenge to the organism. Adaptive immunity displays four characteristic features viz:

1. Antigenic specificity . it is the ability to discriminate among different antigens.

2. Immunologic memory: it is the ability to recall previous contact with a foreign molecule and respond to it in a learned manner, that is , with a more rapid and larger response.

3. Diversity: The ability to respond to different epitopes/antigens, even if the individual has not previously encountered them.

4.Self/ Non-self recognition: it is the ability to recognize and respond to molecules that are foreign and to avoid making a response to those molecules that are are self (self tolerance).

Broadly speaking immunity is of two types:

1. Innate immunity.

2. Adaptive immunity.

1. Innate immunity. it is also called as native/natural immunity. it is present since birth and consists of many factors that are relatively non-specific i.e it operates against almost any foreign molecules and pathogens. it provides the first line of defense against pathogens . it is not specific to any one pathogen but rather acts against all foreign molecules . it also does not rely on previous exposure to a pathogen and response is functional since birth and has no memory.

2. Adaptive immunity.( explained above)

Rate my answer... Good luck