(a) Immune system is essential for our health. Comment on the above statement.(b) How can we acquire immunity?

(a) The immune system of our body is a defence mechanism to fight against pathogenic microbes. It has cells that are specialized to kill infecting microbes and keep our body healthy.
(b) When a person suffers from a disease once, antibodies for these particular disease causing antigens will be formed in the body and he will not get the same disease again. Vaccine also help in acquiring immunity.