Immunotherapy, also known as allergy shots, is a form of treatment used for certain allergies. It can also be helpful in some cases of asthma in which symptoms are triggered by allergies and aren't helped by medications or avoidance of allergens (allergy-causing substances). Immunotherapy involves multiple injections of an allergen over the course of several years. This slowly builds up the body's tolerance to that allergen, which means that the allergic reaction to that specific allergen will eventually decrease in severity.
