ABSTRACT
mRNA vaccines, particularly, have been associated with an increased risk of allergic reactions and rarely anaphylaxis. Although rare, vaccine reactions can cause significant anxiety and fear in the population, leading to indecision and vaccine refusal. This study aimed to retrospectively evaluate the role of polyethylene glycol (PEG) sensitivity in vaccination decision-making in pediatric patients at high risk of allergy or with suspected allergic reactions to the first dose of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) vaccine. Seventeen enrolled patients were found to have decreased readiness to receive the Coronavirus Disease 2019 (COVID-19) vaccine after developing hypersensitivity to multiple and/or injectable drugs. Skin testing was performed. A basophil activation test with PEG-2000 and 4000 was performed on three patients who were ineligible for skin prick tests. Nine patients with negative tests received the vaccine without complications. One patient had urticarial angioedema despite negative tests. Three patients with positive tests did not agree to desensitization with the mRNA vaccine, and one of them was vaccinated with the inactivated COVID-19 vaccine. Four patients recurred despite negative tests. The general recommendation for patients describing severe reactions to drugs, foods, and allergens, such as toxins that do not contain the adjuvants of the SARS-CoV-2 vaccines, is to be routinely vaccinated with safety precautions. Excipients such as PEG and polysorbate-80 used in COVID-19 vaccines could be potential allergens, but this hypothesis is unclear. The predictive values of these adjuvants for skin testing and in vitro testing are controversial. Further research is needed on the hypersensitivity reactions of adjuvants, the predictive values of skin tests, and etiopathogenesis.