An allergy is defined as an immunological reaction by the body in response to the exposure to a foreign material, which is also known as "allergen". Even though there are millions of foreign substances which enter our body through air, water, food, etc., the body detects only some of them as unacceptable and triggers an immune response against them. This response could be in the form of asthma, eczema, hay fever, or other hypersensitivity reactions. There are no specific treatment options for this condition until the cause is diagnosed. In order to start immunotherapy, the allergen that triggered the allergy needs to be identified. Allergy shots or injections, containing specific amounts of the allergens are administered to the person, so that he/she develops immunity against it. The allergen is administered in a quantity which is sufficient to stimulate the immunity, and not cause a full blown reaction. Definition Immunotherapy is defined as the treatment of a particular disease by either inducing or suppressing an immune response, and allergy shots or injections which contain allergens are a form of this therapy. When you develop an allergy to a certain chemical, medicine, food, or any other external substance, the body produces certain antibodies, which battle the infection and try to eradicate it. During this course, certain reactions take place in the body, through which doctors may first diagnose the allergen. In this therapy, the injections include specific amounts of the allergens, which are just enough to stimulate your immune system but not cause a reaction. Over a period of time, the doctor may increase the dose of these shots, in order to help the immune system build tolerance towards the allergen. The commonly found allergens are mold, grasses, pollens, trees, and foods. Working of the Shots As aforementioned, the shots are used to help the body defend itself from the substance that causes the allergy. Usually, the medicines which are given when allergies occur, are only to cover up the symptoms temporarily, and they don't cure the allergies permanently. However, most physicians guarantee their success because they are like vaccines, where a component of the allergen is itself injected in the body. When the doses of these shots are increased, after a particular time, the body stops producing the antibodies, and recognize the allergen as "self". This is because the allergens are already present inside the body, and the immune system has built a friendly relationship with them. Therefore, no reaction is triggered when these allergens enter the body. In this way, they gradually make the body used to the presence of the allergen and cure the allergy eventually. Risks Like all the other forms of immunotherapy, one of the main drawbacks of these shots, is that they have to be continued for about 3 to 5 years or more, continuously. If they are discontinued, then the allergies can return. Sometimes, the allergy might occur immediately after the shots are stopped. Another major risk of using these injections is that the body can generate an immune response, or an allergic reaction to the shots itself. Even though, it is taken care that the shots consist of only a small amount of allergen which doesn't trigger a reaction, sometimes, the reaction may occur. Other than these, there are no other serious side effects involved in getting these shots, when used in proper guidance. If you are susceptible to allergies, and have been looking for a cure, do consult your physician to get some more information about immunotherapy. Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.