Safety and adherence to venom immunotherapy during COVID-19 pandemic

Bilò, M.Beatrice; Braschi, M.Chiara; Piga, Mario A.; Antonicelli, Leonardo; Martini, Matteo

Background According to expert consensus, the time interval between Hymenoptera venom immunotherapy (VIT) injections can be extended up to 12 weeks, without significant impact on efficacy and safety. However, the COVID-19 pandemic caused longer delays, and no recommendations are available to manage this huge extension. Objectives Our study aims to provide advice on how to resume VIT safely after a long delay from the last injection considering the potential risk factors for side effects (SE), without starting again with the induction phase. Methods All the patients who delayed VIT due to pandemic were consecutively enrolled in this single-centre study. The time extension was decided according to their risk profile (e.g. long pre-pandemic time interval, severe pre-VIT reaction, older age, multi-treatments), and correlation analyses were performed to find potential risk factors of SE. Results The mean delay from the pre- (7 weeks) to the post-pandemic VIT interval (15.5 weeks) was 8.5 weeks. The total amount of the pre-pandemic VIT maintenance dose was safely administered in one day in 78% of patients, while only three experienced SE, out of 87, and their potential risk factors were identified in bee venom allergy and recent VIT initiation. Conclusions In a real-world setting, long VIT delays may be safe and well-tolerated, but more caution should be paid in resuming VIT in patients with long pre-pandemic maintenance interval, severe pre-VIT reaction, recent VIT initiation, older age, multi-drug treatments, and bee venom allergy. This is useful in any case of long, unplanned, and unavoidable VIT delay.