More than 20% of the world's population suffers from allergy or allergic asthma and the numbers are rising. Allergic reactions in the eyes and respiratory system are most frequently due to grass or tree or weed pollens, house dust mites or animal danders. In addition, foods may be allergens, as well as various Stinging Insect Venoms and Drugs and Occupational allergens such as latex.

For many of these types of Inhalant Allergens, treatment with allergy Vaccines is not only possible but is highly effective. Immunotherapy is also the only means by which the underlying disease mechanism can be modified, rather than just smothering the symptoms of the body's immune reaction to the allergen.

Traditionally, allergy vaccination has been achieved through the use of a program of Injections administered according to a standard Protocol (or Regime or Scheme). This is known as Sub-Cutaneous Immunotherapy; SCIT. The usual standard SCIT Protocol utilises a series of approximately 15 weekly doses of increasing strength and/or volume of the allergen solution; called the Initial Phase. Once the highest tolerated strength/potency has been achieved, then this becomes the Maintenance Dose and is repeated every 4 to 6 weeks for approx. 3 years. After this three year course of therapy, the course is then either stopped or tailed off, or may be continued for certain highly-sensitised patients.

Most usually the clinical benefit against the targeted allergens (and probably also other potential allergens) persists for several or many years and possibly the patient's lifetime.

Other treatment protocols exist for different Vaccine products and Patient clinical cases, such as Rush or Ultra Rush or Cluster. However, these are most usually reserved for use by an Allergy Specialist in the hospital setting.

Experimental vaccines to treat food allergy, such as peanut allergy or peach allergy, do exist but they are for use only by Allergy Specialists on special clinical cases, and done in the hospital setting.

Most immunotherapy vaccines used in Australia are of the type called "Depot Vaccines" meaning that the allergenic substances (most usually proteins) are adsorbed to a matrix of (most usually) aluminium hydroxide (sometimes calcium phosphate). Therefore when the allergenic material is injected into the patient there is a slow release of the allergen off the matrix and into the patient’s immune system.

Whilst each patient's response to allergy immunotherapy is highly individual, in general most patients will start to experience improvements in symptoms and other medication usage after a few months. After the full 3-year course, remission of symptoms is most usually then complete or at least substantial, and for several years duration or for the lifetime.

It is important to note that vaccination against one particular problem allergen will generally also ameliorate any symptoms from other allergens, and prevent the patient from developing asthma, and will prevent the development of sensitivity against more allergens in the future. This is why there is an increasing trend to identify problem allergens early in the "Allergic March" amongst children, and institute Immunotherapy in order to halt "The Allergic March" towards more severe symptoms, and a greater range of symptoms, and more allergens.