Development and status of allergen immunotherapy (AIT) for pollen allergy: update 2023

Allergen immunotherapy (AIT) has evolved steadily since it was first described by Noon in 1911 and is used worldwide. Its efficacy and safety in the treatment of in-haled allergies such as allergic rhinitis/rhinoconjunctivitis and/or allergic asthma has been extensively demonstrated in clinical trials. The therapy has a disease-modifying effect and significantly improves patients'quality of life. In order to achieve a lasting therapeutic effect, adherence to therapy (also therapy adherence) over the course of therapy, which often lasts several years, is of particular importance. However, various reasons lead to the fact that adherence is generally suboptimal. Individual therapy planning and identification of potential con-founding factors are therefore essential. To improve acceptance, standardized follow-up plans, improved communication and education, and the inclusion of telecommunication technologies such as apps in therapy management are promising. Furthermore, innovations in the development of AIT prod-ucts or alternative routes of administration could help to increase therapy efficacy and adherence. Against this background, further research and clinical development are essential to advance AIT as the only available disease-modifying therapy for the treatment of patients with allergic diseases. Of particular importance are so-called "real-world" studies. "Real-world" studies are especially important for evaluating efficacy under routine conditions. Within the framework of such non-interventional studies, large patient collectives can be examined over a long period of time. These include, for example, analyses of prescription data, registries or the use of digital health applications.