Prick tests and basophil activation tests in hypersensitivity to SARS-CoV-2 vaccines and components

In collaboration with certified allergy centers (CACs) in Germany, a standardized procedure was developed for the allergologic evaluation of hypersensitivity reactions to SARS-CoV-2 vaccines. Our CAC prospectively evaluated 60 subjects with prior allergic reactions to SARS-CoV-2 vaccines or components. The investigations included a comprehensive medical history, in-vitro and skin tests. Prick tests were negative in all participants. Two positive basophil activation tests suggested a hypersensitivity to the component polyethylene glycol; however, no clinical relevance was found. Approximately 73% of the subjects reported symptoms during subsequent immunizations, which were milder than the reactions prior to the diagnostic procedures. Most index reactions manifested as non-specific symptoms. The results suggest that subsequent vaccinations following diagnostic procedures were well tolerated, underscoring the importance of careful allergological evaluation prior to vaccination.