Vaccine is the 'antigen' It is given to person or even to animals for acquiring immunity against particular pathogens or diseases.
Our body reacts to infection by microorganisms by producing certain substances called antibodies. These antibodies kill the invading microorganisms, thereby freeing the body from diseases.
In olden days, in order to protect the body from diseases caused by microorganisms, some dead or weakened microbes are introduced in the body, which cause the production of antibodies. But this method causes some inconvenience.
Hence in recent times the vaccines are produced by using biotechnology. These vaccines are artificial which are synthesised in the
The antigen is produced with the help of gene of the pathogen.
These antibodies then remain in the body for a long period of time protecting the body from diseases. This whole process of introducing vaccines into the body is known as vaccination.