COVID-19 Vaccines: Tolerance of Vaccination in Patients with Allergies

<b>Background</b>: Due to the new COVID-19 vaccine types used in the COVID-19 vaccination program, significant levels of uncertainty and vaccine hesitancy arose due to fears about anaphylactic reactions, especially in patients with allergies. This study aimed to analyze how patients with significant allergies receiving specific immunotherapy (SIT) reacted to COVID-19 vaccines in real life. <b>Methods</b>: We assessed 57 patient charts of individuals with allergies receiving SIT for documented allergies, for their comorbidities, total IgE and tryptase levels, and Hospital Anxiety and Depression Scale (HADS) scores. Questionnaires regarding COVID-19 vaccination status and reported adverse reactions were analyzed. <b>Results</b>: Patients were more frequently male (58%) and had a mean age of 43 years, and the majority (60%) had already experienced an anaphylactic reaction in the past, most commonly to the allergen of the current SIT. In total, 93% received COVID-19 vaccinations. More than half of the patients (57%) reported at least one adverse reaction after COVID-19 vaccination. Out of these patients, 97% reacted in an unspecific way, with symptoms of general illness. One potential allergic reaction, classified as a grade 1 anaphylactic reaction, was documented. The patient with the potential allergic reaction was significantly more concerned before receiving the vaccination and had experienced possible allergic reactions to other vaccinations in the past. The remaining patients with unspecific reactions after vaccination had also experienced such adverse reactions in the past to other vaccinations. Antihistamine premedication was associated with fewer unspecific reactions after COVID-19 vaccination. <b>Conclusions</b>: Vaccinations in patients with significant allergies and prior anaphylactic reactions are, overall, safe. Prior allergic reactions after other vaccinations could be a potential risk for reaction after COVID-19 vaccinations, whereas antihistamine intake could be beneficial in reducing side effects after COVID-19 vaccinations in patients with allergies. Prospective studies on this topic are needed.