Table 2 Gaps in the evidence of AIT for allergic rhinitis

❖ Lack of agreement on clinically relevant outcomes of effectiveness and clinically meaningful effect size of AIT (active vs placebo)

❖ Lack of evidence of clinical effectiveness for some products

❖ Lack of standardized AIT preparations for “orphan allergens”

❖ Lack of evidence for effectiveness of mixtures of homologous allergens

❖ Evidence for long-term clinical effectiveness after discontinuation treatment

❖ Standardization of grading of adverse effects of AIT

❖ Approaches to minimize adverse effects

❖ Good evidence base for contraindicating AIT

❖ Approaches to improve adherence to AIT

❖ Role of adjunctive treatment(s) (e.g. omalizumab)

❖ Cost-effectiveness and cost-utility studies

❖ Good understanding of mechanisms of action

❖ Identification of biomarkers of response, to predict and quantify the effectiveness of AIT

❖ Identification of the most suitable candidates

❖ “Precision medicine” algorithms