The body knows when something foreign enters the system.This can be a reaction like histamines being produced from white blood cells and hay fever is one such result of histamine production. Often, the body reacts by producing antibodies
- You need to know the difference between an antigen and an antibody.
An antibody is a substance produced by the body in response to invasion by a foreign particle of some sort. For example, a pathogen or harmful organism. The body makes antibodies to fight this foreign particle.
Vaccines can prompt the body to make an antibody to a disease. This has the idea of making the body immune to the disease.
Did you know that the first few days of life for a mammal are important as if mother’s milk is consumed by an infant, Colostrum is also consumed? Colostrum contains vital immune substances for the infant.
An antibody is a protein (an immunoglobulin) – Ig (IgA, G, M, D & E).
- Antibodies will bind with an antigen = Antibody>Antigen complex
- Antibodies identify a foreign substance (a pathogen) An antigen is a substance that can initiate an immune response this is why an antibody will bind with an antigen. For example, in the blood grouping system, the antigen-A is found on the surface of the red blood cells of a Type A blood group person. The antibody in the blood of these people is Anti-B.
- Which blood group does a person have if their red blood cells have antigen: B, A & B, No antigen? Answer = B group people have the antigens B, AB group people have A & B, O group people have no antigens at all: these are the Universal Blood donors!
The antibodies in the plasma for these groups are called: A group has Anti-B, B group has Anti-A, AB group people None whatsoever, O group have Anti-A and Anti-B. AB Group people can take blood from anyone as they have no antibodies to other blood groups. These are Universal receivers of blood.
Blood therefore would be regarded by the immune system as a foreign substance if it were the wrong type for the individual.
Two web sites to visit (.pdf files) and read to help with understanding about antibodies and antigens: http://www.moleculartb.org/gb/pdf/transcriptions/11_YZhang.pdf http://www.gih.org/usr_doc/magicbullet.pdf
Quick notes:
- Vaccination leads to active immunity.
- Antibodies acquired naturally, as well as artificially is passive immunity. Natural immunity occurs through the placenta and via lactation (breast feeding in the first few days).
- Magic bullets - This term is used to describe the use of monoclonal antibodies to target specific substances and cells. See the web site references above! This targeting medication to specific cell types is achieved by attaching a therapeutic drug to an antibody. When it attaches its antigen, the antibody can release or bring into contact with the cell, the therapeutic drug.
Uses of this technology - Monoclonal antibodies can be used in medical diagnosis such as for testing for hCG in pregnancy test kits. hCG is Human chorionic gonadotropin. This hormone is secreted by the embryonic membranes and the hCG antigen will cause the antibody to join and give a positive result.
Possible Exam Question: What is your opinion of mass vaccination programmes? Make a list of Advantages and Disadvantages.
