What is the role of vaccination in the immune system?

The correct answer is Option (1) → To generate memory B and T-cells

Vaccination is based on the memory of the immune system. A vaccine brings antigens of a pathogen into the body before any real infection. The body makes antibodies against them, and it also keeps memory B and T-cells ready for the next time.

Option (1) To generate memory B and T-cells — Correct. The memory B and T-cells recognise the pathogen quickly on a later exposure. The body then makes antibodies in large amounts and overcomes the invaders before they can cause disease.

Option (2) To produce antigens — Incorrect. A vaccine supplies the antigens, such as antigenic proteins or an inactivated or weakened pathogen. The body responds to them by making antibodies; it does not make antigens.

Option (3) To enhance innate immunity — Incorrect. Innate immunity is non-specific and present from birth. Vaccination gives acquired (active) immunity, which is specific to the pathogen in the vaccine.

NCERT Extract:
Vaccination and Immunisation – “The principle of immunisation or vaccination is based on the property of ‘memory’ of the immune system. In vaccination, a preparation of antigenic proteins of pathogen or inactivated/weakened pathogen (vaccine) are introduced into the body. The antibodies produced in the body against these antigens would neutralise the pathogenic agents during actual infection. The vaccines also generate memory – B and T-cells that recognise the pathogen quickly on subsequent exposure and overwhelm the invaders with a massive production of antibodies.”
Innate Immunity – “Innate immunity is non-specific type of defence, that is present at the time of birth. This is accomplished by providing different types of barriers to the entry of the foreign agents into our body.”