The following material uses the HowStuffWorks.com article on allergists and immunologists as its primary reference material.
Immunology is concerned with the studyof the immune system, as well as the diagnosis and treatment of disorders related to immunity. This naturally includes the study of allergies, which are a byproduct of the immune system. The body's immune system routinely combats outside forces, whether they be genuine pathogens or merely allergens (i.e. irritating substances that trigger allergic reactions).
Immunologists also study the role of the immune system in cancer growth (see:
oncology). The hope is that they can prevent cancer by modifying the immune
system to reject cancerous growths in the body.
Immunologists are also interested in the opposite effect of the immune system -- the rejection of foreign substances that are actually beneficial. This can occur with organ transplants, as well as with various autoimmune diseases. Ultimately, one would want the immune system to work selectively-allowing the body to reject cancer cells but accept transplanted organs.
An immunologist must complete a residency in internal medicine or pediatrics after graduating from medical school. This residency is followed by a two-year fellowship program in allergy and immunology. Specialty board examinations are also required.
Immunology makes use of a variety of research tools, including flow cytometry, bacterial colony cultures, viral plaque counting, ELISA tests and ELISPOT assays.