Read the following Assertion and Reason and choose the correct option. Assertion: Recombinant DNA technology has enabled the large-scale production of vaccines, such as the hepatitis B vaccine. Reason: Antigenic polypeptides of pathogens can be produced in bacteria or yeast using recombinant DNA technology.

Step-by-step solution

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 produ