Allergy immunotherapy, immunotherapy, "allergy shots" or "allergy vaccines" refer to the induction of resistance to a certain trigger for allergy through the gradual exposure to increasing amounts of the same trigger.
Inhaled allergen immunotherapy (in example to pollen of the olive tree) has been used for decades. When the doctor diagnoses in example allergic rhinitis and decides that the patient's best treatment is with "vaccines", he must inform the patient about a number of facts: it is a long treatment that has two stages, as follows.
- In the first stage, the "building" stage, the patient has to visit the clinic each week in accordance to the vaccination hours of the clinic. The patient will receive increasing doses of the vaccine(s) every week until he achieves the target dose. This stage may typically take about 4-5 months on average.
- In the second stage, the "maintenance" stage, the patient will receive the same vaccine(s) at the dose reached at the end of the "building" phase, but once a month, for 3-5 years. Those who at the end of the "building" phase do not enjoy any improvement in their symptoms will not continue with immunotherapy, in their cases the treatment has failed.
It is important to note that this therapy is not suitable for those who can not comply with this schedule. For the decision to proceed, the patient should consider the risk of local reactions (swelling and pain in the arm, the place of injection), itchy rashes, rare events of shortness of breath. It is important to note that very rare and extreme reactions may occur such as anaphylaxis: a life-threatening condition with choking, blood pressure fall and rashes and that even deaths have been described in the medical literature. Having said that, immunotherapy treatment is a routine treatment that under the right conditions is safe. However, the therapeutic load and logistics and the risk of adverse effects dictate to consider other treatments before considering immunotherapy.
About food allergies, induction of oral desensitization has been used for some years in a number of medical centers in the world, including in Israel and though it is still considered an investigational treatment, the significant experience and impressive results accumulated are encouraging. In this treatment, the food allergic patient receives, during several hours and some days in the hospital, increasing doses of the food to which he is allergic while the allergic effects are treated, so after a few days a threshold of tolerance is reached. The patient will continue to receive this dose of food at home for about a month (again, while treating any adverse reaction, if at all). A month later, a repeat hospitalization is made in order to increase the dose and establish new threshold. Thus that after 3-4 months on average, a state of food tolerance is reached. In other cases the patient can at least raise the threshold for reaction so that the risk of allergy due to food contamination with the allergenic food decreases. This is by itself very important because it lowers the risk of life-threatening reactions.