Give reason why vaccination is done for healthy person

Dear Student, Vaccination is done for healthy person because vaccine contains weak or killed micro-organisms. So, healthy person's immune system can easily fight with the organism and learn how to fight such type of organism. So, when same organism(Stronger) attacks later in life,so our body know the chemicals that need to be released to protect body against this organism and be healthy.This process is known as active Immunity. Regards