(a) How does the human body respond when vaccine is introduced into it?

(b) It is said that vaccinations are a must for a healthy society. Justify.

a) Vaccines are small dose of attenuated or killed microbes that are introduced into the body so as to prepare the body to fight disease next time the same or similar germ infects the body. When vaccines are introduced in the body, T-cells produce antibodies against the vaccine with the help of B-cells and neutralize the pathogen. Then generate a ‘memory’ of the pathogen so when it invades the next time, the B and T cells can attack it.

b) Vaccinations are a must for a healthy society because B and T cells recognize the pathogen and produce antibodies and kill the pathogen. They also create memory of the pathogen and prevent the people in the society from falling sick again. Vaccination also leads to herd immunity.