Immunotherapy and biologics in the management of IgE-mediated food allergy: Systematic review and meta-analyses of efficacy and safety.

Food allergy (FA) is a potentially life-threatening chronic condition that is becoming an increasing public health problem worldwide. This systematic review (SR) was carried out to inform the development of clinical recommendations on the treatment of IgE-mediated FA with biologics and/or IT for the update of the EAACI guidelines. A SR of randomized-controlled trials or quasi-controlled trials was carried out. Studies were identified via comprehensive search strategies in Medline, Embase, and Cochrane Library, up to April 2022. POPULATION: Human adults, children, and adolescents with IgE-mediated FA. INTERVENTION: IT and/or biologics. COMPARATOR: Placebo or standard-of-care (allergen avoidance). OUTCOME: Efficacy (desensitization, sustained unresponsiveness (SU), remission), quality of life, and safety (systemic and local adverse reactions (AR)). The Cochrane RoB tool was used to assess the risk of bias. It was reported according to PRISMA and registered in PROSPERO CRD4202229828. After screening, 121 studies were included (111 for IT and 10 for biologics). Most studies had a high risk of bias and showed high heterogeneity in design and results. Metanalysis showed a positive effect of biologics and IT in terms of relative risk (RR) for achieving tolerance to the culprit food compared to avoidance or placebo. Omalizumab for any FA showed a RR of 2.17 [95% confidence interval: 1.22, 3.85]. For peanut allergy, oral IT (OIT) had a RR of 11.94 [1.76, 80.84] versus avoidance or placebo, sublingual IT (SLIT) had a RR of 3.00 [1.04, 8.66], and epicutaneous IT (EPIT) of 2.16 [1.56, 3.00]. OIT had a RR of 5.88 [2.27, 15.18] for cow's milk allergy, and of 3.43 [2.24, 5.27] for egg allergy. There was insufficient data on SLIT or EPIT for the treatment of egg and milk allergies. Most ARs reported were mild. For OIT the most common AR involved the gastrointestinal system and for EPIT, AR's most commonly affected the skin. There was limited data on severe or life-threatening ARs. There was limited evidence for long term efficacy and quality of life. In conclusion, biologics and IT, alone or in combination, are effective in achieving desensitization while on active treatment but more evidence is needed on long-term tolerance as current evidence is not of high quality. Adverse events while on therapy are generally mild to moderate but a long-term comprehensive safety profile is missing. There is a critical need to optimize and standardize desensitization protocols and outcome measures to facilitate our understanding of the efficacy and safety as well as to allow for comparison between interventions.

The skin microbiome in pediatric atopic dermatitis and food allergy.

The skin microbiome is an extensive community of bacteria, fungi, mites, viruses and archaea colonizing the skin. Fluctuations in the composition of the skin microbiome have been observed in atopic dermatitis (AD) and food allergy (FA), particularly in early life, established disease, and associated with therapeutics. However, AD is a multifactorial disease characterized by skin barrier aberrations modulated by genetics, immunology, and environmental influences, thus the skin microbiome is not the sole feature of this disease. Future research should focus on mechanistic understanding of how early-life skin microbial shifts may influence AD and FA onset, to guide potential early intervention strategies or as microbial biomarkers to identify high-risk infants who may benefit from possible microbiome-based biotherapeutic strategies. Harnessing skin microbes as AD biotherapeutics is an emerging field, but more work is needed to investigate whether this approach can lead to sustained clinical responses.

Systematic review and meta-analyses on the accuracy of diagnostic tests for IgE-mediated food allergy.

The European Academy of Allergy and Clinical Immunology (EAACI) is updating the Guidelines on Food Allergy Diagnosis. We aimed to undertake a systematic review of the literature with meta-analyses to assess the accuracy of diagnostic tests for IgE-mediated food allergy. We searched three databases (Cochrane CENTRAL (Trials), MEDLINE (OVID) and Embase (OVID)) for diagnostic test accuracy studies published between 1 October 2012 and 30 June 2021 according to a previously published protocol (CRD42021259186). We independently screened abstracts, extracted data from full texts and assessed risk of bias with QUADRAS 2 tool in duplicate. Meta-analyses were undertaken for food-test combinations for which three or more studies were available. A total of 149 studies comprising 24,489 patients met the inclusion criteria and they were generally heterogeneous. 60.4% of studies were in children ≤12 years of age, 54.3% were undertaken in Europe, ≥95% were conducted in a specialized paediatric or allergy clinical setting and all included oral food challenge in at least a percentage of enrolled patients, in 21.5% double-blind placebo-controlled food challenges. Skin prick test (SPT) with fresh cow's milk and raw egg had high sensitivity (90% and 94%) for milk and cooked egg allergies. Specific IgE (sIgE) to individual components had high specificity: Ara h 2-sIgE had 92%, Cor a 14-sIgE 95%, Ana o 3-sIgE 94%, casein-sIgE 93%, ovomucoid-sIgE 92/91% for the diagnosis of peanut, hazelnut, cashew, cow's milk and raw/cooked egg allergies, respectively. The basophil activation test (BAT) was highly specific for the diagnosis of peanut (90%) and sesame (93%) allergies. In conclusion, SPT and specific IgE to extracts had high sensitivity whereas specific IgE to components and BAT had high specificity to support the diagnosis of individual food allergies.

Evaluation of clinical outcomes of efficacy in food allergen immunotherapy trials, COFAITH EAACI task force.

Food allergy is a global public health problem that until recent years lacked any aetiological treatment supported by academy, industry and regulators. Food immunotherapy (AIT) is an evolving treatment option, supported by clinical practice and industry trial data. Recent AIT meta-analyses have highlighted the difficulty in pooling safety and efficacy data from AIT trials, due to secondary heterogeneity in the study. An EAACI task force (CO-FAITH) initiated by the Paediatric Section was created to focus on AIT efficacy outcomes for milk, egg and peanut allergy rather than in trial results. A systematic search and a narrative review of AIT controlled clinical trials and large case series was conducted. A total of 63 manuscripts met inclusion criteria, corresponding to 23, 21 and 22 studies of milk, egg and peanut AIT, respectively. The most common AIT efficacy outcome was desensitization, mostly defined as tolerating a maintenance phase dose, or reaching a particular dose upon successful exit oral food challenge (OFC). However, a large degree of heterogeneity was identified regarding the dose quantity defining this outcome. Sustained unresponsiveness and patient-reported outcomes (e.g. quality of life) were explored less frequently, and to date have been most rigorously described for peanut AIT versus other allergens. Change in allergen threshold assessed by OFC remains the most common efficacy measure, but OFC methods suffer from heterogeneity and methodological disparity. This review has identified multiple heterogeneous outcomes related to measuring the efficacy of AIT. Efforts to better standardize and harmonize which outcomes, and how to measure them must be carried out to help in the clinical development of safe and efficacious food allergy treatments.

Maternal and Infant Dietary Patterns Are Not Related to Food Allergy Risk in Singapore Children: GUSTO Cohort Study.

BACKGROUND: We previously reported that delayed allergenic food introduction in infancy did not increase food allergy risk until age 4 y within our prospective cohort. However, it remains unclear whether other aspects of maternal or infant diet play roles in the development of childhood food allergy. OBJECTIVES: We examined the relationship between maternal pregnancy and infant dietary patterns and the development of food allergies until age 8 y. METHODS: Among 1152 Singapore Growing Up in Singapore Towards healthy Outcomes study mother-infant dyads, the infant's diet was ascertained using food frequency questionnaires at 18 mo. Maternal dietary patterns during pregnancy were derived from 24-h diet recalls. Food allergy was determined through interviewer-administered questionnaires at regular time points from infancy to age 8 y and defined as a positive history of allergic reactions, alongside skin prick tests at 18 mo, 3, 5, and 8 y. RESULTS: Food allergy prevalence was 2.5% (22/883) at 12 mo and generally decreased over time by 8 y (1.9%; 14/736). Higher maternal dietary quality was associated with increased risk of food allergy (P ≤ 0.016); however, odds ratios were modest. Offspring food allergy risk ≤8 y showed no associations with measures of infant diet including timing of solids/food introduction (adjusted odds ratio [aOR]: 0.90; 95% confidence interval [CI]: 0.42, 1.92), infant's diet quality (aOR: 0.93; 95% CI: 0.88, 0.99) or diet diversity (aOR: 0.84; 95% CI: 0.6, 1.19). Most infants (89%) were first introduced to cow milk protein within the first month of life, while egg and peanut introduction were delayed (58.3% introduced by mean age 8.8 mo and 59.8% by mean age 18.1 mo, respectively). CONCLUSIONS: Apart from maternal diet quality showing a modest association, infant's allergenic food introduction, diet quality, and dietary diversity were not associated with food allergy development in this Asian pediatric population. Interventional studies are needed to evaluate the efficacy of these approaches to food allergy prevention across different populations.

EAACI guidelines on environmental science in allergic diseases and asthma - Leveraging artificial intelligence and machine learning to develop a causality model in exposomics.

Allergic diseases and asthma are intrinsically linked to the environment we live in and to patterns of exposure. The integrated approach to understanding the effects of exposures on the immune system includes the ongoing collection of large-scale and complex data. This requires sophisticated methods to take full advantage of what this data can offer. Here we discuss the progress and further promise of applying artificial intelligence and machine-learning approaches to help unlock the power of complex environmental data sets toward providing causality models of exposure and intervention. We discuss a range of relevant machine-learning paradigms and models including the way such models are trained and validated together with examples of machine learning applied to allergic disease in the context of specific environmental exposures as well as attempts to tie these environmental data streams to the full representative exposome. We also discuss the promise of artificial intelligence in personalized medicine and the methodological approaches to healthcare with the final AI to improve public health.

EAACI guidelines on the diagnosis of IgE-mediated food allergy.

This European Academy of Allergy and Clinical Immunology guideline provides recommendations for diagnosing IgE-mediated food allergy and was developed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Food allergy diagnosis starts with an allergy-focused clinical history followed by tests to determine IgE sensitization, such as serum allergen-specific IgE (sIgE) and skin prick test (SPT), and the basophil activation test (BAT), if available. Evidence for IgE sensitization should be sought for any suspected foods. The diagnosis of allergy to some foods, such as peanut and cashew nut, is well supported by SPT and serum sIgE, whereas there are less data and the performance of these tests is poorer for other foods, such as wheat and soya. The measurement of sIgE to allergen components such as Ara h 2 from peanut, Cor a 14 from hazelnut and Ana o 3 from cashew can be useful to further support the diagnosis, especially in pollen-sensitized individuals. BAT to peanut and sesame can be used additionally. The reference standard for food allergy diagnosis is the oral food challenge (OFC). OFC should be performed in equivocal cases. For practical reasons, open challenges are suitable in most cases. Reassessment of food allergic children with allergy tests and/or OFCs periodically over time will enable reintroduction of food into the diet in the case of spontaneous acquisition of oral tolerance.

Pathogenesis, immunology, and immune-targeted management of the multisystem inflammatory syndrome in children (MIS-C) or pediatric inflammatory multisystem syndrome (PIMS): EAACI Position Paper.

Multisystem inflammatory syndrome in children (MIS-C) is a rare, but severe complication of coronavirus disease 2019 (COVID-19). It develops approximately 4 weeks after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and involves hyperinflammation with multisystem injury, commonly progressing to shock. The exact pathomechanism of MIS-C is not known, but immunological dysregulation leading to cytokine storm plays a central role. In response to the emergence of MIS-C, the European Academy of Allergy and Clinical Immunology (EAACI) established a task force (TF) within the Immunology Section in May 2021. With the use of an online Delphi process, TF formulated clinical statements regarding immunological background of MIS-C, diagnosis, treatment, follow-up, and the role of COVID-19 vaccinations. MIS-C case definition is broad, and diagnosis is made based on clinical presentation. The immunological mechanism leading to MIS-C is unclear and depends on activating multiple pathways leading to hyperinflammation. Current management of MIS-C relies on supportive care in combination with immunosuppressive and/or immunomodulatory agents. The most frequently used agents are systemic steroids and intravenous immunoglobulin. Despite good overall short-term outcome, MIS-C patients should be followed-up at regular intervals after discharge, focusing on cardiac disease, organ damage, and inflammatory activity. COVID-19 vaccination is a safe and effective measure to prevent MIS-C. In anticipation of further research, we propose a convenient and clinically practical algorithm for managing MIS-C developed by the Immunology Section of the EAACI.

Food immunotherapy practice: Nation differences across Europe, the FIND project.

BACKGROUND: Food allergen immunotherapy (FA-AIT) practice is known to vary globally. This project aims to identify and characterize European centres performing FA-AIT. METHODS: An EAACI task force conducted an online survey to gather relevant information regarding FA-AIT practice and setting-specific resources after reviewing the published literature and congress abstracts throughout Europe. RESULTS: We identified 102 FA-AIT centres in 18 countries; only Spain (n = 39) and France (n = 16) had ≥10 such centres. Overall, most facilities were hospital-based (77.5%), publicly funded (80.4%) and delivered FA-AIT as routine clinical care (80.4%). On average, departments had 3 allergists/paediatric allergists and 2 nurses. Surveyed centres had provided FA-AIT for a median of 9 years [1-24] to a median of 105 [5-2415] patients. The estimated total number of treated patients was 24875, of whom 41.3% received AIT for milk, 34.2% egg, 12.8% peanut and 11.7% other foods. Anaphylaxis to AIT doses requiring over 4-6 h of observation was reported by 70.6% of centres, ICU admissions by 10.8% and eosinophilic esophagitis by 45.1%. Quality of life and sustained unresponsiveness were evaluated in 20.6% and 54.9% of centres, respectively. The main contraindications for food AIT were severe asthma (57%-63%), eosinophilic esophagitis (56%-48%) and age below 5 years (47%-41%). CONCLUSIONS: In Europe, FA-AIT is provided mostly in clinical practice. Significant variation is seen in the number of centres per country, facility characteristics and inclusion/exclusion criteria, and in certain aspects of protocols. Potential inequality in access to AIT has been identified as well as the need for education and guidance for treatment standardization.

EAACI guidelines: Anaphylaxis (2021 update).

Anaphylaxis is a clinical emergency which all healthcare professionals need to be able to recognize and manage. The European Academy of Allergy and Clinical Immunology Anaphylaxis multidisciplinary Task Force has updated the 2014 guideline. The guideline was developed using the AGREE II framework and the GRADE approach. The evidence was systematically reviewed and recommendations were created by weighing up benefits and harms. The guideline was peer-reviewed by external experts and reviewed in a public consultation. The use of clinical criteria to identify anaphylaxis is suggested with blood sampling for the later measurement of tryptase. The prompt use of intramuscular adrenaline as first-line management is recommended with the availability of adrenaline autoinjectors to patients in the community. Pharmacokinetic data should be provided for adrenaline autoinjector devices. Structured, comprehensive training for people at risk of anaphylaxis is recommended. Simulation training and visual prompts for healthcare professionals are suggested to improve the management of anaphylaxis. It is suggested that school policies reflect anaphylaxis guidelines. The evidence for the management of anaphylaxis remains mostly at a very low level. There is an urgent need to prioritize clinical trials with the potential to improve the management of patients at risk of anaphylaxis.

Protocol for a systematic review of the diagnostic test accuracy of tests for IgE-mediated food allergy.

BACKGROUND: The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of updating the guidelines on the diagnosis and management of food allergy. The existing guidelines are based on a systematic review of the literature until 30 September 2012. Therefore, a new systematic review must be undertaken to inform the new guidelines. This systematic review aims to assess the accuracy of index tests to support the diagnosis of IgE-mediated food allergy. METHODS: The databases Cochrane CENTRAL (Trials), MEDLINE (OVID) and Embase (OVID) will be searched for diagnostic test accuracy studies from 1 October 2012 to 30 June 2021. Inclusion and exclusion criteria will be used to select appropriate studies. Data from these studies will be extracted and tabulated, and then reviewed for risk of bias and applicability using the QUADAS-2 tool. All evaluations will be done in duplicate. Studies with a high risk of bias and low applicability will be excluded. Meta-analysis will be performed if there are three or more studies of the same index test and food. RESULTS: A protocol for the systematic review and meta-analyses is presented and was registered using Prospero prior to commencing the literature search. DISCUSSION: Oral food challenges are the reference standard for diagnosis but involve considerable risks and resources. This protocol for systematic review aims to assess the accuracy of various tests to diagnose food allergy, which can be useful in both clinical and research settings.

EAACI statement on the diagnosis, management and prevention of severe allergic reactions to COVID-19 vaccines.

The first approved COVID-19 vaccines include Pfizer/BioNTech BNT162B2, Moderna mRNA-1273 and AstraZeneca recombinant adenoviral ChAdOx1-S. Soon after approval, severe allergic reactions to the mRNA-based vaccines that resolved after treatment were reported. Regulatory agencies from the European Union, Unites States and the United Kingdom agree that vaccinations are contraindicated only when there is an allergy to one of the vaccine components or if there was a severe allergic reaction to the first dose. This position paper of the European Academy of Allergy and Clinical Immunology (EAACI) agrees with these recommendations and clarifies that there is no contraindication to administer these vaccines to allergic patients who do not have a history of an allergic reaction to any of the vaccine components. Importantly, as is the case for any medication, anaphylaxis may occur after vaccination in the absence of a history of allergic disease. Therefore, we provide a simplified algorithm of prevention, diagnosis and treatment of severe allergic reactions and a list of recommended medications and equipment for vaccine centres. We also describe potentially allergenic/immunogenic components of the approved vaccines and propose a workup to identify the responsible allergen. Close collaboration between academia, regulatory agencies and vaccine producers will facilitate approaches for patients at risks, such as incremental dosing of the second injection or desensitization. Finally, we identify unmet research needs and propose a concerted international roadmap towards precision diagnosis and management to minimize the risk of allergic reactions to COVID-19 vaccines and to facilitate their broader and safer use.

Diagnosing, managing and preventing anaphylaxis: Systematic review.

BACKGROUND: This systematic review used the GRADE approach to compile evidence to inform the European Academy of Allergy and Clinical Immunology's (EAACI) anaphylaxis guideline. METHODS: We searched five bibliographic databases from 1946 to 20 April 2020 for studies about the diagnosis, management and prevention of anaphylaxis. We included 50 studies with 18 449 participants: 29 randomized controlled trials, seven controlled clinical trials, seven consecutive case series and seven case-control studies. Findings were summarized narratively because studies were too heterogeneous to conduct meta-analysis. RESULTS: It is unclear whether the NIAID/FAAN criteria or Brighton case definition are valid for immediately diagnosing anaphylaxis due to the very low certainty of evidence. There was also insufficient evidence about the impact of most anaphylaxis management and prevention strategies. Adrenaline is regularly used for first-line emergency management of anaphylaxis but little robust research has assessed its effectiveness. Newer models of adrenaline autoinjectors may slightly increase the proportion of people correctly using the devices and reduce time to administration. Face-to-face training for laypeople may slightly improve anaphylaxis knowledge and competence in using autoinjectors. We searched for but found little or no comparative effectiveness evidence about strategies such as fluid replacement, oxygen, glucocorticosteroids, methylxanthines, bronchodilators, management plans, food labels, drug labels and similar. CONCLUSIONS: Anaphylaxis is a potentially life-threatening condition but, due to practical and ethical challenges, there is a paucity of robust evidence about how to diagnose and manage it.

Vaccines and allergic reactions: The past, the current COVID-19 pandemic, and future perspectives.

Vaccines are essential public health tools with a favorable safety profile and prophylactic effectiveness that have historically played significant roles in reducing infectious disease burden in populations, when the majority of individuals are vaccinated. The COVID-19 vaccines are expected to have similar positive impacts on health across the globe. While serious allergic reactions to vaccines are rare, their underlying mechanisms and implications for clinical management should be considered to provide individuals with the safest care possible. In this review, we provide an overview of different types of allergic adverse reactions that can potentially occur after vaccination and individual vaccine components capable of causing the allergic adverse reactions. We present the incidence of allergic adverse reactions during clinical studies and through post-authorization and post-marketing surveillance and provide plausible causes of these reactions based on potential allergenic components present in several common vaccines. Additionally, we review implications for individual diagnosis and management and vaccine manufacturing overall. Finally, we suggest areas for future research.

COVID-19 pandemic and allergen immunotherapy-an EAACI survey.

BACKGROUND: As in many fields of medical care, the coronavirus disease 2019 (COVID-19) resulted in an increased uncertainty regarding the safety of allergen immunotherapy (AIT). Therefore, the European Academy of Allergy and Clinical Immunology (EAACI) aimed to analyze the situation in different countries and to systematically collect all information available regarding tolerability and possible amendments in daily practice of sublingual AIT (SLIT), subcutaneous AIT (SCIT) for inhalant allergies and venom AIT. METHODS: Under the framework of the EAACI, a panel of experts in the field of AIT coordinated by the Immunotherapy Interest Group set-up a web-based retrospective survey (SurveyMonkey® ) including 27 standardized questions on practical and safety aspects on AIT in worldwide clinical routine. RESULTS: 417 respondents providing AIT to their patients in daily routine answered the survey. For patients (without any current symptoms to suspect COVID-19), 60% of the respondents informed of not having initiated SCIT (40% venom AIT, 35% SLIT) whereas for the maintenance phase of AIT, SCIT was performed by 75% of the respondents (74% venom AIT, 89% SLIT). No tolerability concern arises from this preliminary analysis. 16 physicians reported having performed AIT despite (early) symptoms of COVID-19 and/or a positive test result for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). CONCLUSIONS: This first international retrospective survey in atopic diseases investigated practical aspects and tolerability of AIT during the COVID-19 pandemic and gave no concerns regarding reduced tolerability under real-life circumstances. However, the data indicate an undertreatment of AIT, which may be temporary, but could have a long-lasting negative impact on the clinical care of allergic patients.

COVID-19 pandemic: Practical considerations on the organization of an allergy clinic-An EAACI/ARIA Position Paper.

BACKGROUND: The coronavirus disease 2019 (COVID-19) has evolved into a pandemic infectious disease transmitted by the severe acute respiratory syndrome coronavirus (SARS-CoV-2). Allergists and other healthcare providers (HCPs) in the field of allergies and associated airway diseases are on the front line, taking care of patients potentially infected with SARS-CoV-2. Hence, strategies and practices to minimize risks of infection for both HCPs and treated patients have to be developed and followed by allergy clinics. METHOD: The scientific information on COVID-19 was analysed by a literature search in MEDLINE, PubMed, the National and International Guidelines from the European Academy of Allergy and Clinical Immunology (EAACI), the Cochrane Library, and the internet. RESULTS: Based on the diagnostic and treatment standards developed by EAACI, on international information regarding COVID-19, on guidelines of the World Health Organization (WHO) and other international organizations, and on previous experience, a panel of experts including clinicians, psychologists, IT experts, and basic scientists along with EAACI and the "Allergic Rhinitis and its Impact on Asthma (ARIA)" initiative have developed recommendations for the optimal management of allergy clinics during the current COVID-19 pandemic. These recommendations are grouped into nine sections on different relevant aspects for the care of patients with allergies. CONCLUSIONS: This international Position Paper provides recommendations on operational plans and procedures to maintain high standards in the daily clinical care of allergic patients while ensuring the necessary safety measures in the current COVID-19 pandemic.

A compendium answering 150 questions on COVID-19 and SARS-CoV-2.

In December 2019, China reported the first cases of the coronavirus disease 2019 (COVID-19). This disease, caused by the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2), has developed into a pandemic. To date, it has resulted in ~9 million confirmed cases and caused almost 500 000 related deaths worldwide. Unequivocally, the COVID-19 pandemic is the gravest health and socioeconomic crisis of our time. In this context, numerous questions have emerged in demand of basic scientific information and evidence-based medical advice on SARS-CoV-2 and COVID-19. Although the majority of the patients show a very mild, self-limiting viral respiratory disease, many clinical manifestations in severe patients are unique to COVID-19, such as severe lymphopenia and eosinopenia, extensive pneumonia, a "cytokine storm" leading to acute respiratory distress syndrome, endothelitis, thromboembolic complications, and multiorgan failure. The epidemiologic features of COVID-19 are distinctive and have changed throughout the pandemic. Vaccine and drug development studies and clinical trials are rapidly growing at an unprecedented speed. However, basic and clinical research on COVID-19-related topics should be based on more coordinated high-quality studies. This paper answers pressing questions, formulated by young clinicians and scientists, on SARS-CoV-2, COVID-19, and allergy, focusing on the following topics: virology, immunology, diagnosis, management of patients with allergic disease and asthma, treatment, clinical trials, drug discovery, vaccine development, and epidemiology. A total of 150 questions were answered by experts in the field providing a comprehensive and practical overview of COVID-19 and allergic disease.

EAACI Allergen Immunotherapy User's Guide.

Allergen immunotherapy is a cornerstone in the treatment of allergic children. The clinical efficiency relies on a well-defined immunologic mechanism promoting regulatory T cells and downplaying the immune response induced by allergens. Clinical indications have been well documented for respiratory allergy in the presence of rhinitis and/or allergic asthma, to pollens and dust mites. Patients who have had an anaphylactic reaction to hymenoptera venom are also good candidates for allergen immunotherapy. Administration of allergen is currently mostly either by subcutaneous injections or by sublingual administration. Both methods have been extensively studied and have pros and cons. Specifically in children, the choice of the method of administration according to the patient's profile is important. Although allergen immunotherapy is widely used, there is a need for improvement. More particularly, biomarkers for prediction of the success of the treatments are needed. The strength and efficiency of the immune response may also be boosted by the use of better adjuvants. Finally, novel formulations might be more efficient and might improve the patient's adherence to the treatment. This user's guide reviews current knowledge and aims to provide clinical guidance to healthcare professionals taking care of children undergoing allergen immunotherapy.