Question : What is the basic principle of vaccination ? How do vaccines prevent microbial infections ? Name the organism from which hepatitis B Vaccine is produced.

Question : What is the basic principle of vaccination ? How do vaccine

1.	Question : What is the basic principle of vaccination ? How do vaccines prevent microbial infections ? Name the organism from which hepatitis B Vaccine is produced.
Answer» Solution :The PRINCIPLE of vaccination is based on the property of .MEMORY. of the immune system . In vaccination, a preparation of antigenic proteins of pathogens or inactivated/live but weakened pathogens is introduced into the BODY. The antigens generate the primary immune RESPONSE by producing antibodies. The vaccines also generate the memory B-cells and T-cells. When the vaccinated person is attacked by the same pathogens, the existing memory B-cells or T-cells recognise the ANTIGEN quickly and overwhelm the invaders with massive production of lymphocytes and antibodies. Hepatitis B vaccine is produced from yeast.