The role of the allergist in COVID-19 vaccine allergy safety: A pilot study on a "Hub-and- Spoke" model for population-wide allergy service

ABSTRACT

Background: Hong Kong started its territory-wide COVID-19 vaccination program in February 2021. A territory-wide VAS (Vaccine Allergy Safety) Clinic was set up to assess individuals deemed at "higher risk" of COVID-19 vaccine-associated allergies. A novel "Hub-and- Spoke" model was piloted to tackle the overwhelming demand of VAS services by allowing non-allergists to conduct allergy assessment. This study aims to evaluate the outcomes and effectiveness of the VAS Hub-and- Spoke Model for pre-vaccination allergy assessment. Method(s) Medical records of patients attending the VAS Hub and Spoke Clinics between March and August 2021 were reviewed (n = 2725). We studied the overall and comparative results between the Hub (allergist-led) and Spoke (non-allergist- led) Clinics. The Hub and the HKWC Spoke Clinic were selected for subgroup analysis as they saw the largest number of patients (n = 1411). Result(s) A total of 2725 patients were assessed under the VAS Hub-and- Spoke Model. Overall, 2324 patients (85.3%) were recommended to proceed with vaccination (Figure 1). There were no significant demographic differences noted. Allergists recommended significantly more patients for vaccination than non-allergists (OR = 21.58 [95% CI = 10.16-45.82], p < 0.001). Subgroup analysis revealed that 881/1055 (83.5%) of patients received their first dose of COVID-19 vaccination safely following assessment. Among those recommended vaccination, more patients assessed by allergists received their first dose of COVID-19 vaccination (OR = 4.18 [95% CI = 2.81-6.21], p < 0.001) (Table 1). Conclusion(s) The Hub-and- Spoke model has proven to be successful for the vaccination campaign. This study has illustrated the crucial role of allergists in countering vaccine hesitancy. Results from the study showed considerable differences in outcomes between allergist-led and non-allergist clinics. Precise reasons for these differences warrant further examination. We are hopeful the Hub-and Spoke model can be similarly adapted for other allergist-integrative services in the future.