Allergy shots are regular injections taken over several years that help stop or reduce allergy attacks. They can be used to control symptoms triggered by seasonal allergies, such as hay fever or pollen, indoor allergies, such as dust mites or pet dander, or insect stings, such as bees or wasps.
Each shot contains a tiny amount of the substance that triggers your allergic reactions to stimulate your immune system, but not enough to cause a full-blown allergic reaction. Over time, the dose of allergens in each of shot is increased, helping you get used to the allergens. Your immune system then builds up a tolerance to the allergens, causing your allergy symptoms to diminish over time.