Our body’s resistance to a particular foreign particle is known as the immunity of our body against that infection. Immunity is nothing but the defense against diseases as well as infections. This process of defending our body against infectious agents is known as immunization.

When an infectious particle enters our body our body fights against it and renders it ineffective. It succeeds in eliminating those harmful substances. The foreign material entering our body is known as the ‘antigen’. Our body produces certain substances to fight against these antigens and they are known as antibodies. These antibodies react with the antigens and render them ineffective.

The antigen is responsible for causing the infection. These antigens can be complete as well as incomplete. If it is capable of inducing antibody formation this process is known as antigenicity. If the antigen is not capable of inducing an immune response it is said to be incomplete. Incomplete antigens are known as haptens. Haptens can only elicit antibody formation but not the immune response.

How are these antibodies produced? Our immune system is made of various kinds/ types of cells which produce these antibodies. The cells include the B cells and the T cells.

The B cells produce soluble antibodies whereas the T cells produce membrane bound antibodies.

These antibodies are the substances which are responsible for fighting against the foreign harmful substances which are the antigens and rendering them ineffective. This way our body is able to recover from any disease which it encounters.