Leveraging COVID-19 vaccine allergy evaluations with coincident drug allergy delabelling: Effectiveness and impact on quality of life

Abstract

Background: Concerns of potential drug/vaccine-associated allergies significantly impact vaccine safety and hesitancy. Delabelling of incorrect drug allergy in the general public was previously impeded by limited access to allergist services, especially among less frequent healthcare utilisers in the community. COVID-19 vaccine allergy evaluation services have enabled individuals (mis)labelled with allergies to receive vaccinations safely and have provided opportunities to expand drug allergy delabeling access. We investigated the effectiveness of this coincident drug allergy delabelling and its impact on health-related quality of life (HRQoL). Methods: We recruited individuals labelled with drug allergies attending for COVID-19 vaccine evaluation in Hong Kong between 2021 and 2022. Demographics, comorbidities, drug allergy labels, COVID-19 vaccination and infection outcomes, as well as coincident delabelling rates were analysed. HRQoL was measured before and after evaluation in a subgroup of individuals. Results: Among 652 individuals, 1456 drug allergy labels were identified, with anti-infectives being the most common (606, 41.6 %). Beta-lactam antibiotics accounted for 55.1 % (334). Almost all individuals (99.4 %) safely proceeded with COVID-19 vaccinations, with an increased number of doses conferring better protection. 228 (35.0 %) individuals underwent drug allergy investigations, with coincident drug allergy delabelling successful in 223 (97.8 %), removing 317 (21.8 %) incorrect labels, of which 173 (51.8 %) were beta-lactams. Subgroup analysis showed improved serial health-related quality of life following delabelling (DrHy-Q 45.0 vs 33.3, p < 0.001). Conclusion: Services evaluating COVID-19 vaccine allergies have not only empowered individuals labelled with drug allergy to receive vaccinations safely, but have also enhanced access to drug allergy delabeling services for the general public.