plz tell is immunisation process is only occur by vaccines
or it is also a process in which our body fights without vaccines
Answers
The environment contains a wide variety of potentially harmful organisms (pathogens), such as bacteria, viruses, fungi, protozoa and multicellular parasites, which will cause disease if they enter the body and are allowed to multiply. The body protects itself through a various defence mechanisms to physically prevent pathogens from entering the body or to kill them if they do.
The immune system is an extremely important defence mechanism that can identify an invading organism and destroy it. Immunisation prevents disease by enabling the body to more rapidly respond to attack and enhancing the immune response to a particular organism.
Each pathogen has unique distinguishing components, known as antigens, which enable the immune system to differentiate between ‘self’ (the body) and ‘non-self’ (the foreign material). The first time the immune system sees a new antigen, it needs to prepare to destroy it. During this time, the pathogen can multiply and cause disease. However, if the same antigen is seen again, the immune system is poised to confine and destroy the organism rapidly. This is known as adaptive immunity.
Vaccines utilise this adaptive immunity and memory to expose the body to the antigen without causing disease, so that when then live pathogen infects the body, the response is rapid and the pathogen is prevented from causing disease. Depending on the type of infectious organism, the response required to remove it varies. For example, viruses hide within the body’s own cells in different tissues, such as the throat, the liver and the nervous system, and bacteria can multiply rapidly within infected tissues.