**10. Future perspectives**

As it mentioned above clinical efficacy of immunotherapy has been proven in a great number of clinical studies but there are still some issues to be discussed. Recent studies are more focused on the usage of recombinant allergen-based immunotherapy that will possible makes allergy vaccines more safe, convenient, and effective. Recombinant-allergen vaccines also contain defined amounts of the allergen components, and the composition can be tailored according to patient's sensitizations. Both recombinant allergen-diagnostic tests and immunotherapy lead to more personalized and stratified treatment of different allergic entities. Recombinant allergen-based vaccines have been developed and successfully evaluated for several respiratory allergen sources including food allergies [117–120]. The second approach for minimizing side effects and improves compliance is the usage of peptide immunotherapy that has been proven in many studies as effective in treating patients with different respiratory allergies [121]. Data from the studies showed that this kind of immunotherapy is clinical effective for months to years after a short course of treatment. Some studies also investigate new routes of administration such as intralymphatic and epicutaneous. Although it is proven as safe and efficacy, both routes require further clinical investigation [122, 123]. Recently, scientists have exploited the immune system to produce antibodies from single B cell clones, heralding the era of monoclonal antibodies. Biological agents (biologicals or biologics) bring revolution in the treatment of many rheumatic and immunological disorders and are currently being assessed for allergic disorders. Better understanding the endotypes and phenotypes of allergic disease may lead to specifically targeting the responsible molecular mechanism by a biological. The mechanism of biologicals implies the inhibition of a specific molecule involved in allergic inflammation, without weakening immunity against viruses and bacteria. The design and use of biologicals requires a profound understanding of the mechanisms underlying allergy. Several biologicals are being assessed in clinical trials, including biologicals inhibiting interleukin (IL)-4, IL-5, IL-9, IL-13, and immunoglobulin E, but most of them are still being tested in clinical trials, involving patients with allergic asthma, allergic rhinitis, food allergy, urticaria, atopic eczema, and diseases with high eosinophil counts. It is to be expected that biologicals will replace or reduce the use of the currently prescribed unspecific pharmacotherapy of allergic inflammation. Better understanding of disease endotypes, identification of novel biomarkers, and discovery of novel biologicals are the cornerstones of the modern approach in treating allergic diseases [124–127].
