Write a short note on Vaccination.

Ans. Vaccination:- The principle of vaccination is based on the memory

of immune system. In it the preparation 

of antigenic proteins of pathogens or weakened pathogen \ Vaccine is 

introduced into the body. 

These antigen generate primary 

immune response and memory B

and T-cells. When vaccinated person 

is attached by the same pathogen, 

the existing B and T cells recognize

 the antigen and produce antibodies

 and lymphocytes.

इन्हे भी पढ़िए :-- 

What is cancer? Name and explain the different categories of cancer. Or, Comment upon Cancer.