Question

Explain how does vaccine work?

Answer 1

A vaccine is a small quantity of a weakened antigen that is injected into the body of an individual. Once the antigen gets into the body of a healthy person, his/her body synthesises antibodies against the antigen. Once the body encounters an infectious antigen, it develops a memory; and when that antigen enters that body again, a large amount of antibodies is secreted by the body to destroy the antigen. Hence, it prevents the disease from occurring.