Two types of immunotherapy are available.
If your asthma is triggered by an allergy, you should consider allergy shots, which are very effective in relieving allergy symptoms and in some cases can actually cure your allergy. The treatment, which can take several years, builds up immunity to your offending allergens (pollens, dust mite, pets, mold). It works by injecting small amounts of the allergen in gradually increasing amounts over time. As the shots help the body build up a tolerance to the effects of the allergen, they eventually reduce and can even eliminate your allergy symptoms.
This type of immunotherapy was approved by the Food and Drug Administration in 2014. Starting several months before allergy season begins, patients dissolve a tablet under the tongue daily. Treatment can continue for as long as three years. These medications should not be used in patients with severe or uncontrolled asthma. Only a few allergens (certain grass and ragweed pollens) can be treated now with this method, but it is a promising therapy for the future.