Question

How can you immunise an individual against disease?

Answer 1

$\bullet$Immunisation is the process by which a person becomes protected against a disease through vaccination.

$\bullet$ Vaccines are preparations consisting of weakened germs or dead germ substances that triggers an immune response within the body.

$\bullet$ When they enter the body, they cannot cause the disease, instead prompt the immune system to produce antibodies in response to the specific antigens.

$\bullet$These antibodies fight against the antigens by antigen-antibody reaction.

$\bullet$ After killing the antigens, the antibodies are destroyed, but some immune cells called memory cells remain in the body.

$\bullet$ When the same pathogen attacks the person again, these memory cells produce antibodies immediately and kill the antigens before they cause the disease.

$\bullet$ Thus, a vaccine can confer active immunity against a specific harmful agent by stimulating the immune system to attack the agent.