Evaluation of the Autoimmunity and Preexisting Risky Conditions for Hypersensitivity Reactions to COVID-19 Vaccines

Introduction: The role of autoimmunity and other preexisting risky conditions in hypersensitivity reactions (HSRs) to COVID-19 vaccines seems unclear. The aim of the study was to investigate the autoimmunity and preexisting risky conditions in HSRs to COVID-19 vaccines. Methods: The patients aged ≥18 years with a history of HSR to CoronaVac or Pfizer-BioNTech COVID-19 vaccines within 24 h in 2 tertiary centers were assessed. The patients were divided according to the type of vaccine which they showed immediate-type (<4 h) HSR to (group A1 for CoronaVac and group B1 for Pfizer-BioNTech). Equal number of subjects who did not show HSR to two doses of either CoronaVac or Pfizer-BioNTech was recruited into the study as control groups (group A2 for CoronaVac and group B2 for Pfizer-BioNTech). The autologous serum skin test (ASST) was performed on patient and control groups. Later, the demographic, clinical, and laboratory features were compared between groups. Results: A total number of 27 patients were included in the study. Subjects with chronic spontaneous urticaria (CSU) were more frequent in group B1 than in group B2 (p:0.041). In addition to CSU, the presence of HSRs to drugs was higher in group A1 than in A2 (both p:0.007). The presence of autoimmunity and autoimmune diseases, positivity of antithyroid peroxidase antibody, and ASST were less in group A2 than in A1 (p:0.015, p:0.048, p:0.048, and p:0.037). Additionally, COVID-19 infection history was less in group A2 than in A1 (p:0.037). Discussion/Conclusion: Type IIb autoimmunity seems to play a role in immediate type HSRs to the CoronaVac vaccine as previously shown in autoimmune CSU and multidrug hypersensitivity.