Ask the Allergist: How Long Are Allergy Shots Effective?



SublettQ: “I had allergy shots when I was a child. Now I’m in my 50s. Will those allergy shots still protect me?” 

James Sublett, MD: Protection from allergies with immunotherapy, or allergy shots, doesn’t stop due to age. Allergy shots are as effective for people over the age of 50 as they are for children and young adults. If you had immunotherapy when you were younger and wonder if you need to do it again, I would say it depends on whether allergies are again disrupting your daily life.

Allergy shots lead to a long-lasting reduction of symptoms for many people; others may lose their immunity at some point and choose to resume allergy shots.

Immunotherapy treats most inhalant allergens such as pollen, mold, pet dander, dust mites and cockroaches, as well as insect venom allergens, and it is especially beneficial for people with multiple allergies.

Like a vaccine protects against infection, allergy shots suppress the part of the immune system that triggers the allergic response.

Here’s how allergy shots work: A patient with a confirmed allergy will initially undergo a series of injections that contain the allergic substance, gradually building up to a weekly maintenance dose. Depending on the schedule used, this may take anywhere from 1 to 4 months. This helps your body tolerate your allergens.

Once the maintenance dose is reached, the intervals of the shots containing the same amount of allergen are gradually extended out to about four weeks and may be continued for 3-5 years. If the patient is doing well after that period and no longer needs most or all of their allergy medications, the immunotherapy may be discontinued. In many cases, the immunity will continue for years.

If you are experiencing difficult-to-control allergy symptoms as an adult – even if you had allergy shots as a child or teenager – see a board-certified allergist to discuss your testing and treatment options.

It might not be the old allergies returning. It’s possible you’ve developed an allergy to something different; perhaps you moved to a new environment or you’re in a different workplace, and you’re exposed to new allergens. You may have developed other allergic conditions or are experiencing allergy symptoms again requiring medications.

Age is not a barrier to starting an immunotherapy regimen and undergoing them once does not preclude you from doing it again. The right therapy will protect you way beyond your 50s.


James Sublett, MD, FACAAI, FAAP, is president of the American College of Allergy, Asthma & Immunology. He is a board-certified allergist with Family Allergy & Asthma in Louisville, Kentucky.


Have a medical question? Email editor@allergyasthmnanetwork.org or write to “Ask the Allergist,” Allergy & Asthma Network, 8229 Boone Blvd., Suite 260, Vienna, VA 22182.


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