Background: Environmental exposure chambers (EECs) have been used extensively to study allergic rhinoconjunctivitis. Few studies have been published using EECs in conjunctivitis only, and none have used conjunctival allergen challenge as a selection criterion. The present study validated ALYATEC EEC in allergic conjunctivitis to birch allergens. Methods: Sixteen patients with a positive conjunctival allergen challenge (CAC) were ex-posed to 60 ng/m3 of Bet v 1 in an EEC on 2 consecutive days for a maximum of 4 hours. Re-producibility was tested among seven of the patients. A positive conjunctival response during the CAC and the EEC exposure was defined as a Total Ocular Symptom Score (TOSS) ≥ 5. Results: Fifty percent of patients had a positive conjunctival response during the first expo-sure and 75% during the second. The mean time to a positive conjunctival response was 81.2±33.9 minutes and 101.6±57 (P>0.05) during the first and second exposure, respectively. No difference in the TOSS occurred between the two exposures. The time necessary to ob-tain a positive response during the CAC was significantly shorter than with the EEC. The es-timated quantity of Bet v 1 inducing a positive response was 0.07±0.03 ng (exposure 1), 0.07±0.07 ng (exposure 2), 980±784 ng (CAC). The frequency of conjunctival responses and quantity of Bet v 1 was reproducible in all six EEC exposures. Conclusions: Birch allergen exposures inducing early conjunctival responses were different than those identified with direct installation during CAC. EEC appears to be closer to natural exposure than CAC.

Staphylococcal Enterotoxins sensitization and response of Omalizumab in severe atopic and non atopic asthma Nicolas Migueres1,2, Anh Poirot1, Nan Zhang ,3,4, Claus Bachert 3,4, Frédéric de Blay1 ,51: Chest Diseases Department, Strasbourg University Hospital, Strasbourg France.2: UMR 7357 Laboratoire des sciences de l’ingénieur, de l’informatique et de l’imagerie ICUBE3: Upper Airways Research Laboratory, Ghent University, Ghent, Belgium4: Division of ENT diseases, CLINTEC, Karolinska Institute, University of Stockholm, Sweden5: EA 3072, Fédération de médecine translationnelle, université de Strasbourg, 67000 Strasbourg, FranceCorresponding author: Nicolas Migueres, [email protected] Diseases DepartmentNouvel Hôpital CivilHopitaux Universitaires de Strasbourg67093 STRASBOURG CEDEXtel: 00 33 6 07 60 51 86,Total word count ( 570 words)Author Contributions: All investigators contributed to the conception and design of the study. All authors contributed to the acquisition, analysis and interpretation of the data. They provided input into the drafting of the manuscript, critical feedback, and final approval for submission of the manuscript for publication. NM is the guarantor of the final content of the manuscript.The authors have no conflicts of interest to declare.

NK cells and Lipoxin A4 promote resolution of eosinophilic inflammation after nasal allergen challenge

Immune modulation is a key therapeutic tool for allergic diseases and asthma. It can be achieved in an antigen-specific way via allergen immunotherapy (AIT) or in endotype-driven approach using biologicals that target the major pathways of the type 2 (T2) immune response: IgE, IL-5 and IL-4/IL-13. COVID-19 vaccine provides an excellent opportunity to tackle the global pandemics and is currently being applied in an accelerated rhythm worldwide. It works as well through immune modulation. Thus, as there is an obvious interference between these treatment modalities recommendations on how they should be applied in sequence are expected. The European Academy of Allergy and Clinical Immunology (EAACI) gathered an outstanding expert panel under its Research and Outreach Committee (ROC). This expert panel was called to evaluate the evidence and formulate recommendation on the administration of COVID-19 vaccine in patients with allergic diseases and asthma receiving AIT or biologicals. The panel also formulated recommendations for COVID-19 vaccine in association with biologicals targeting the type 1 or type 3 immune response. In formulating recommendations, the panel evaluated the mechanisms of COVID-19 infection, of COVID-19 vaccine, of AIT and of biologicals and considered the data published for other anti-infectious vaccines administered concurrently with AIT or biologicals.

Background: Allergy is witnessing major advances, in particular with the advent of biological therapies for treating allergic diseases. Given the novelty of these therapeutics, we aimed to explore by a worldwide survey, the prescription and the management of hypersensitivity reactions (HR) of biological agents (BA) in Allergy. Method: We built up an anonymous online questionnaire, sent out by mail and social media and circulated for 40 days. Results: 348 responses were from 59 countries, with a majority from Europe (62.6%). 97% of responders practiced allergy and 48.5%, exclusively so. Allergy was mentioned as a full specialty in 69.5 % of cases. 71% of responders confirmed the right of prescription of BA for allergists in their country and 78.4 % prescribed BA in their clinical practice. Europe included almost all the allergists who did not have the right of prescribing BA (95.5%), specifically France (91%). The most prescribed BA were Anti IgE (78.1%) and anti IL5 (43.9%). The most declared HR to BA were local reactions (74.1%) followed by anaphylaxis like symptoms (6.8%) and delayed exanthemas (5.1%). Desensitization was considered in 18.9% of cases. These HR were reported in 48.8% of cases. Conclusion: Although BA are now a pillar in the treatment of allergic diseases and allergists are familiar with management of HR associated with BA, their prescription is not authorized for allergists in all countries. BA showed to be generally safe but HR, which may be severe, could occur with a lack of consensus on the management.