Anaphylaxis associated with the mRNA COVID-19 vaccines: Approach to allergy investigation

Area of Science:

• Immunology
• Vaccinology
• Allergy and Clinical Immunology

Background:

• Reports of anaphylaxis following mRNA vaccination have raised public concern and potentially increased vaccine hesitancy.
• Current diagnostic approaches lack standardized protocols for allergy testing to mRNA vaccines.
• Polyethylene glycol (PEG), an excipient in mRNA vaccines, is recognized for its allergenic potential and is implicated in recent increases in allergy diagnoses.

Purpose of the Study:

• To address the need for standardized allergy testing protocols for mRNA vaccines.
• To propose evidence-based protocols for diagnosing hypersensitivity reactions to mRNA vaccines, focusing on polyethylene glycol (PEG) as the likely allergen.
• To highlight the complexity and risks associated with allergy testing for mRNA vaccines and PEGs.

Main Methods:

• Review of current knowledge on potential mechanisms of anaphylaxis associated with mRNA vaccines.
• Assumption that polyethylene glycol (PEG) is the primary causative agent in vaccine-related anaphylaxis.
• Proposal of diagnostic strategies for PEG and mRNA vaccine hypersensitivity.

Main Results:

• Polyethylene glycol (PEG) is identified as the most probable allergen responsible for anaphylaxis post-mRNA vaccination.
• Allergy testing for PEGs and mRNA vaccines is complex and carries an inherent risk of inducing anaphylaxis.
• Patients with a history of systemic allergic reactions to multiple drug classes may be at higher risk for PEG allergy.

Conclusions:

• Allergy testing for mRNA vaccines and polyethylene glycol (PEG) requires specialized drug allergy centers due to complexity and risk.
• Readily available PEG-free emergency medical treatment and supervision are crucial for managing potential anaphylactic reactions.
• Development and implementation of standardized allergy testing protocols are essential to manage vaccine hypersensitivity and mitigate public anxiety.