Antibodies are basically a powerful and intelligent defender of the immune system. The immune defence system can be split into two parts ~ the lymphocytes (these are white blood cells, found in the lymph as well as the bloodstream) and antibodies for the other part of the immune defences. Antibodies are produced by two types of lymphocytes: B cells and T cells.

Fundamental to antibodies is their branching structure which means they can lock onto invading microorganisms or to any poison which these organisms are producing. But they can also 'mark' any invading materials, through their special cells (known as macrophones) which then go on to destroy any invaders.

Not satisfied with this, antibodies also stick to foreign cells and mobilise groups of blood proteins (known as a complement) which break up the foreign cells and kill them. Scientists think that this process actually calls scavenging cells to the area of conflict and they can be killed !

 An antibody is a complex protein molecule otherwise known as immunoglobulin. It is a Y shaped molecule that is made by a B lymphocyte in response to a molecule on the surface of a bacteria, virus, parasite or other foreign invading particle that tries to set up an infection in the body.

Antibodies bind to the molecule on the surface of the invader and this helps to destroy it.

Once an infection begins, it takes a while for B cells to recognise the foreign molecules and then form the antibodies that neutralise them. This takes maybe a few days but the speed and size of the response is increased if the molecule has been seen before. This is thanks to special B lymphocytes called memory cells that remember a molecule and then produce lots of antibodies more quickly when they come across it again.

This is the principle behind childhood vaccination.