question_answer 8)

Differentiate between following and give examples of each: (a) Innate and acquired immunity. (b) Active and passive immunity.  

Answer:

  (a)  

Innate immunity	Acquired immunity
1. It is present from birth.	It develops during life time.
2. The immunity remains throughout life.	The acquired immunity can be short lived or life long.
3. Innate immunity is inheritable.	Acquired immunity cannot be passed to the next generation except for a brief period to neonates.
4. It protects the individual from contraction of diseases of other organisms.	It protects the individuals from pathogens present on other members of the same species.
5. Examples – Innate immunity against distemper, a fatal disease of dog, acid in the stomach and mucus coating of epithelium preventing microbial growth, interferons protecting non-infected cells from further viral infections are all examples of innate immunity.	Examples – Vaccination, infants immunity, inoculation of antisera, etc are examples of acquired immunity.

  (b)

Active immunity	Passive immunity
1. It is produced due to contact with pathogen or its antigen.	It is produced due to obtaining antibodies from outside.
2. Immunity is not immediate. A time lapse occurs for its development.	Immunity develops immediately.
3. It lasts for sufficiently long period, may be life long.	It lasts for a few days.
4. Antibodies are produced by the body in response to pathogen or antigen.	Antibodies are obtained from outside.
5. Side effects are very few.	At time the body reacts to the introduction of antisera. It is called serum sickness.
6. Examples – Bacterial vaccines, viral vaccines, bacterial products such as toxoids for diphtheria and tetanus. Subclinical or clinical infections are examples of active immunity.	Examples – IgG crossing placental barriers, human colostrum, antitetanus serum (ATS), antidiphtheric serum (ADS), anti-gas gangerene serum (AGS) are examples of passive immunity.