May polyethylene glycol be the cause of anaphylaxis to mRNA COVID-19 vaccines?

Vaccination against coronavirus is essential to minimize the impact of the COVID-19 pandemic. Rare cases of anaphylaxis associated with the mRNA COVID-19 vaccines are being described, and the mechanisms involved in these reactions are poorly understood. A potential culprit agent of these vaccine-induced anaphylaxis events is polyethylene glycol, which has been reported as a cause of anaphylaxis. However, a cause-effect association has not been demonstrated, and the cases of anaphylaxis to mRNA COVID-19 vaccines should be further investigated. In this scenario, the recommendations are inaccurate and can lead to misinterpretation. At the moment, a more accurate recommendation would be the contraindication of mRNA COVID-19 vaccines in patients with immediate hypersensitivity reaction to polyethylene glycol or polysorbate. Patients with history of anaphylaxis to other or unknown causes should be referred to an allergist-immunologist for further orientation.