Answer the following

What are vaccines?

Vaccines are substances which are injected to a person. It consists of killed or weakened pathogens (disease causing microorganisms). They are introduced in the body of human beings at a very early age. This weakened pathogens cause very mild harm to the body in result of which the body produces antibodies against that pathogen. Whenever the same pathogen enters our body, the body produces exaggerated reaction in response to the pathogen.

The principal behind vaccination is that whenever a microorganism enters in a body, the defense mechanism of that particular body gets activated and it starts producing antibodies against that particular pathogen. Even after the pathogen is removed out from the body, the body will always remember to produce those particular antibodies against that pathogen. If that particular pathogen encounters with the body once again, the body will now show exaggerated response and will produce antibodies very quickly against that pathogen.

So in vaccination, a weak and dead form of some pathogen is introduced in the body so that the body will produce antibodies against it and when actual infection will occur, it can easily respond against it to protect the body and thus body will get immunized.