IMMUNIZATION STRESS-RELATED RESPONSES DURING SKIN TESTING AND CHALLENGE TO COVID-19 VACCINES: A CASE SERIES

INTRODUCTION: While IgE-mediated hypersensitivity to COVID-19 vaccines may occur, many adverse reactions (ARs) to COVID-19 vaccination are non-immunologic in nature and meet criteria for immunization stress-related response (ISRR). METHODS: Patients were referred to our allergy clinic for skin testing (prick with undiluted vaccine, intradermal with 1:100, 1:10, and undiluted vaccine) and graded challenge with COVID-19 vaccines (Pfizer, Moderna, or Johnson and Johnson) between July 2021 and June 2022. ARs were documented and treated accordingly. ARs were characterized as ISRR based on the World Health Organization diagnostic criteria or non-ISRR if symptoms were outside those criteria. RESULTS: 83 patients underwent skin testing (ST) and/or graded challenge (GC) with COVID-19 vaccines in our office. Twenty-six (31.3%) patients had one or more symptoms of AR in the immediate period following ST/GC while 57 patients completed vaccination without any AR. 15 patients (1 to ST, 14 to challenge dose) had symptoms consistent with ISRR. 14 of these patients completed full vaccine dose. No patients had any significant objective changes in physical exam. 11 patients had ARs not meeting ISRR criteria. The most reported symptom in this cohort was subjective pruritus. 6 of these patients were able to complete full vaccination dose. CONCLUSION: Most patients with AR consistent with ISRR successfully completed full COVID-19 vaccine administration. Some patients with symptoms suggestive of histamine-mediated reaction had no objective findings and were also able to complete vaccination. Our experience highlights the need to consider ISRR in evaluation of vaccine reactions and supports the safety of COVID-19 vaccination in patients with ISRR.