CoronaVac/Sinovac COVID-19 Vaccine-Related Hypersensitivity Reactions and Second-Dose Vaccine Administration: Tertiary Allergy Center Experience

Introduction: The COVID-19 pandemic has caused a global health crisis. To prevent the disease, the Ministry of Health of Turkey gained approval for the CoronaVac COVID-19 vaccine for emergency use as the first-line. This study aimed to evaluate patients who developed hypersensitivity reactions (HRs) due to the CoronoVac vaccine and to share our experience of administering the second dose of vaccine to these patients. Methods: The study group included the patients who presented to the Ege University Allergy and Immunology Division between January and May 2021. Demographic data, atopic status, allergic reactions to the first dose of the COVID-19 vaccine and the route of second-dose vaccine administrations were recorded. Results: A total of 7 patients (four healthcare professionals), 6 (86%) of whom were women, with an average age of 53.4 years, were included in the study. The rate of allergic reactions among Ege University health workers was 0.036% (2/5,558). Six of our patients had a history of additional allergic diseases and comorbid diseases. None had any allergic reactions to previous vaccinations and latex allergy. Reactions developed commonly on the skin, as generalized urticaria/angioedema and pruritus. The severity of the reactions was evaluated as mild in 2, moderate in 3, and severe in 2 cases. The second-dose CoronaVac was safely administered by using a gradually increase dose in a total of 6 patients. Conclusion: In patients with HRs due to Sinovac in the first dose, the second dose can be safely performed using a gradually increased dose.