Safety and Adherence to Venom Immunotherapy During COVID-19 Pandemic

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 coronavirus disease 2019 pandemic caused longer delays, and no recommendations are available to manage this huge extension.

Objectives: 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, without starting again with the induction phase.

Methods: All the patients who delayed VIT because of the pandemic were consecutively enrolled in this single-center study. The time extension was decided according to their risk profile (eg, long prepandemic time interval, severe pre-VIT reaction, older age, multitreatments), and correlation analyses were performed to find potential risk factors of side effects.

Results: The mean delay from the pre- (7 weeks) to the postpandemic VIT interval (15.5 weeks) was 8.5 weeks. The total amount of the prepandemic VIT maintenance dose was safely administered in 1 day in 78% of patients, whereas only 3, of 87, experienced side effects, 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 prepandemic maintenance interval, severe pre-VIT reaction, recent VIT initiation, older age, multidrug treatments, and bee venom allergy. This is useful in any case of long, unplanned, and unavoidable VIT delay.