Allergy is a global health problem with a large proportion of population affected, and the prevalence continues to grow. Allergen immunotherapy is the only treatment providing long-term relief, but current protocols take very long time, need strict patient’s compliance and demonstrate rather low efficacy. E.g. the gold standard, subcutaneous/sublingual allergen immunotherapy, requires at least 3 years of therapy to achieve sustainable results. We propose a novel approach for allergen immunotherapy (AIT), which is based on the delivery of selected allergen peptides, produced by genetically-modified bacteria directly in the nasal cavity of a patient. This approach might have several crucial advantages, compared to gold standard oral allergen immunotherapy.