Allergy Shots (immunotherapy)
Allergy subcutaneous immunotherapy (allergy shots) is a form of treatment that decreases allergic symptoms for many people suffering from environmental or stinging insect allergy. It may improve eye, nose, skin or breathing symptoms and can reduce the risk of severe allergic reactions to stinging insects such as honeybees.
Allergy shots may provide lasting relief of symptoms even after treatment is stopped. This makes it a cost-effective, beneficial treatment approach.
Who can benefit from allergy shots?
Patients as young as five years old can receive allergy shots if a board-certified allergist determines environmental items like grass pollen or dust mites are causing symptoms.
Some of the reasons for starting shots may include:
• Length of allergy season and severity of symptoms
• How well medications and/or environmental controls are helping symptoms
• The desire to avoid long-term medication use
• Time available for treatment (allergy shots require a significant time commitment)
• Cost (which may vary depending on region and insurance coverage)
How do allergy shots work?
Allergy shots work by giving you the allergens you are allergic to in gradually increasing doses and over time you may develop an improved tolerance. There are two phases:
• Build-up phase: Allergy shots are given approximately once or twice per week in gradually increasing amounts. This phase may take between four to six months to complete.
• Maintenance phase: This begins once the final effective dose is reached after building up your tolerance. Once in maintenance phase, allergy shots are typically given every two to four weeks and continued for three to five years.
What is the difference between the type of allergy shot schedules?
There are different allergy shot schedules depending on what is available at your allergy clinic. Compared to the traditional shot schedule, there may be options for cluster, rush and ultra-rush therapy. The only difference between them is the rate at which you complete the build-up phase.
• Traditional Immunotherapy: Patients initially come weekly for allergy shots then are gradually spaced up to once monthly when they reach the maintenance phase. The build-up phase can take between four to six months to complete.
• Cluster Immunotherapy: These shots accelerate the build-up phase by giving a handful of shots (e.g. up to four shots in one visit) once or twice a week until maintenance is reached. This can significantly shorten the build-up phase by at least one to two months.
• Rush Immunotherapy: Patients may receive a series of shots (e.g. up to seven shots) within a clinic visit followed by weekly injections. This can speed up completion of the build-up phase to several weeks instead of months. There are higher risks for reactions with rush immunotherapy compared to traditional and cluster immunotherapy.
• Ultra-Rush Immunotherapy: This is primarily for urgent start of venom immunotherapy in patients with life-threatening allergic symptoms to stinging insects (e.g. honeybee, yellow jacket, hornet). The build-up phase may be completed in hours or days and are generally well-tolerated. The risk for shot reactions on venom immunotherapy are comparable between accelerated or conventional build-up schedules.
Although cluster, rush and ultra-rush offer options to accelerate the build-up phase to reach maintenance shots quicker, there is also the potential for increased risk of shot reactions. To minimize this risk, patients can be prescribed pre-treatment medications such as an antihistamine (e.g. cetirizine or fexofenadine) and corticosteroids (e.g. prednisone) several days before starting their shots. It is important to talk to your allergist when considering allergy shots about these options, including their risks and benefits to see which options work best for you.
How effective are allergy shots?
Allergy shots can be highly effective at reducing allergy symptoms and improving quality of life. Allergy shots may also help prevent the development of new allergies, and in children, it may help reduce the risk of asthma. Allergy shots are most likely to have lasting relief of symptoms if completed for at least three years or longer. If you have not seen improvement after a year of maintenance therapy, your allergist will work with you to find more treatment options.
Where should allergy shots be given?
Allergy shots should be given in a health care setting. The facility should be equipped with proper staff and equipment necessary to identify and treat reactions if needed. Allergy shots are not recommended for home administration.
Are there risks?
Common side effects of allergy shots may include localized redness and swelling at the injection site. Widespread severe allergy reactions, known as anaphylaxis, are rare but may occur.
When severe reactions do occur, they require immediate medical attention. Symptoms can include hives, swelling, throat tightness, shortness of breath, nausea, vomiting and/or diarrhea. Fatal reactions are exceedingly rare but have been reported. It is best to talk with your doctor about risks and benefits of allergy shots.
References
1. Lee MC, Puglisi LB, Kelso JM. Comparison of Standard, Cluster, and Rush Allergy Immunotherapy Buildup Protocols. J Allergy Clin Immunol Pract. 2023 Sep;11(9):2884-2889. doi: 10.1016/j.jaip.2023.06.028. Epub 2023 Jun 25. PMID: 37369309; PMCID: PMC10527491.
2. Bernstein, J. A., Bernstein, J. S., Makol, R., & Ward, S. (2024). Allergic rhinitis: a review. Jama, 331(10), 866-877.
3. Greiwe J, Bernstein JA. Accelerated/rush allergen immunotherapy. Allergy Asthma Proc. 2022;43(4):344-349. doi:10.2500/aap.2022.43.210108
4. Biagi M, Pucci C, Puxeddu I, Migliorini P, Dolcher MP. Ultrarush protocol safety and efficacy in Hymenoptera venom immunotherapy. Ann Allergy Asthma Immunol. 2025;135(6):676-680. doi:10.1016/j.anai.2025.07.020
5. Golden, D. B., Demain, J., Freeman, T., Graft, D., Tankersley, M., Tracy, J., ... & Wallace, D. (2017). Stinging insect hypersensitivity: a practice parameter update 2016. Annals of Allergy, Asthma & Immunology, 118(1), 28-54.
Kermit Zhang, MD
Department of Allergy, Asthma, & Immunology
Scripps Clinic, San Diego, CA
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9/16/2026