Allergological clarification of suspected COVID-19 vaccine allergy in the Christmas week 2021: organization and findings of a pilot study

Background: In 2020 the COVID-19 pandemic spread due to the coronavirus SARS-CoV-2. Vaccination is crucial to fight the COVID-19 pandemic. Initial reports of anaphylaxis after vaccination caused con -cern and fear of the population and conse-quently a high demand for allergy testing.Methods: The need and reasons for allergy testing were recorded via questionnaires and the patients' medical history. To study the possibility of higher-throughput allergy evaluation, additional new skin test ap-pointment slots were created for patients concentrated during the Christmas week 2021 and the amount of material, time re-quired, as well as the organization and the tolerability of subsequent vaccination were analyzed.Results: The demand for testing greatly exceeded the number of available standard appointment slots. Test indications were mostly the patients' fear of an allergic reaction to the vaccine when a polyethyl-ene glycol (PEG) allergy could not be un-equivocally excluded in the patients' history. Forty-one patients (38 females, 3 men, age 51 +/- 17.7) were tested on 3 days. The aver-age contact time needed per patients for the nurse was 30 minutes and for the physician 25 minutes. One patient could not be tested due to antihistamine use. After testing, in 36 cases routine vaccination was recommend-ed; of those 35 patients got vaccinated. In four patients, an indication for inpatient PEG provocation or inpatient vaccination was given. Two thirds (27/41 patients, 65.9%) of all who were initially refusing vaccination got vaccinated shortly after allergy tests and tolerated this vaccination without major complications, an additional 9.8% intended future vaccination. Only four patients (9.8%) persistently refused vaccination after test-ing.Conclusions: In this pilot study, we show a useful and effective option to triage pa-tients requesting COVID-19 vaccine allergy testing and generally how to process allergy appointments in a more time effective man-ner. Optimizing intraclinical processes leads to a substantially higher number of patients that can be allergy tested and vaccinated.