ABSTRACT
Background: Sars-CoV- 2 infections are hazardous, especially to the elderly and patients with comorbidities. With no efficient treatment available, newly developed vaccines are the only way to change the course of the pandemic. However, reports of allergic reactions resulted in some patients and practising physicians being concerned about the safety of vaccine administration, particularly in people with severe anaphylactic reactions to multiple or unknown factors in their medical history. This study aimed to develop an allergic workup protocol based on skin prick tests (SPT), intradermal testing (IDT) and intramuscular provocations, and desensitization which may contribute to diagnosis and management of anti-COVID- 19 vaccine allergy. Method(s): 285 patients were enrolled. 205 of them entered the study based on severe anaphylactic reaction to unknown or multiple factors in their medical history which disqualified them for standard treatment. Another 80 patients were enrolled after developing an allergic reaction to the first dose of one such vaccine. In all subjects, SPT and IDT were performed with one of 4 available vaccines. Result(s): 277 patients with negative tests were given a vaccine without complications. Six patients with positive skin tests received desensitization with a reasonable tolerance. One patient did not consent to desensitization and one patient resigned despite negative tests. All in all, 283 (99%) patients were vaccinated using this newly developed protocol. Patients with adverse reactions to the first dose of the vaccine before the study had a significantly lower basal serum tryptase concentration (p = 0.001). Conclusion(s): Skin tests with anti-COVID- 19 vaccines are a useful tool in the vaccination protocol. This protocol enables safe immunization of high-allergy- risk patients even cases of positive skin tests.