Patients with suspected allergic reactions to COVID‐19 vaccines can be safely revaccinated after diagnostic work‐up

Abstract

Background: When initiating the Danish vaccination program against COVID-19, the incidence of anaphylaxis was estimated to be 10 times higher compared to other virus-based vaccines. In this study, we present data on patients referred with suspected allergic reactions to COVID-19 vaccines. The main purpose of the study is to investigate the incidence and severity of the allergic reactions, and to evaluate the safety of revaccination. Methods: All patients in the region of Southern Denmark with case histories of allergic reactions to COVID-19 vaccines in a defined period are included in this study. Diagnostic work up consisted of a detailed case history, evaluation of Brighton level of diagnostic certainty and World Allergy Organization grade of anaphylaxis and skin prick testing-and basophil histamine release testing with COVID-19 vaccines and relevant drug excipients. Patients were revaccinated at the Allergy Center when possible.Results: Sixty-one patients are included in this study. In 199,377 doses administered, nine patients fulfilled the criteria of anaphylaxis when using the Brighton Criteria (incidence being 45 per million). Of 55 patients with reactions to the first dose, 52 patients were revaccinated without adverse reactions. We found no proven cases of immediate anaphylaxis due to COVID-19 vaccines. By skin prick test, we diagnosed three patients with drug excipient allergy and further a patient with mastocytosis was found.Conclusions: Anaphylactic reactions to COVID-19 vaccines are rare and the incidence is similar to what is seen with other virus-based vaccines. Revaccination is safe in the majority of patients; however, allergological evaluation is important since some prove to have drug excipient allergy.

Recent advances and developments in COVID‐19 in the context of allergic diseases

“… 136 An allergological work‐up for patients with a possible risk of severe hypersensitivity reactions is recommended. 137 The patients should be evaluated with skin tests for the vaccine and its excipients. Alternative vaccines that do not contain the suspected components could be considered in case of a positive skin result.…”

Allergy to polyethylene glycol and polysorbates in a patient cohort: Diagnostic work‐up and decision points for vaccination during the COVID‐19 pandemic

“… 6 During the COVID‐19 epidemic focus has been on these two excipients as they are excipients in the first vaccines on the market in Europe and possible culprits for allergic reactions to the COVID‐19 vaccines. 7 , 8 , 9 , 10 …”

“…We have recently published results on anaphylactic reactions to COVID‐19 vaccines in the normal population and found the incidence to be similar to other virus‐based vaccines. 10 Of 55 patients with reactions to the first dose 52 patients were re‐vaccinated without adverse reactions. Three patients were diagnosed with allergy to drug excipients.…”

The Polysorbate containing AstraZeneca COVID‐19 vaccine is tolerated by polyethylene glycol (PEG) allergic patients

“…However, after investigation, true allergy is rarely found and many are not IgE mediated 1 and are often labelled immunogenic reactions. Recent studies have shown successful revaccination in patients who had suspected allergic reactions to their first dose 2,3 . Polysorbate 80 (PS80) is the potentially allergenic excipient in the AstraZeneca and Janssen/Johnson and Johnson COVID‐19 vaccines.…”