Investigators detail the clinical criteria of the condition and speak to the safety of the COVID-19 vaccine for this patient population.
An investigation into the implications of polyethylene glycol (PEG) allergy and its potential to elicit anaphylaxis to COVID-19 mRNA vaccines concluded that patients with PEG allergy could be safely vaccinated against the virus.
However, specific individual recommendations for the vaccination approach were suggested and dependent on risk analysis and shared decision making.
Polyethylene glycols are a part of a family of hydrophilic polymers produced by polymerization of ethylene oxide, which are used extensively in medicine including laxatives and other intestinal cleaning solutions, liquid cosmetics, emulsions, and more.
However, PEG 2000 is also a component in the artificial lipid layer in the SARS-CoV-2 mRNA vaccines of both Moderna and Pfizer-BioNTech, and is the only excipient in COVID-19 mRNA vaccines demonstrated to cause delayed-type and immediate-type allergic reactions.
Led by Tilo Biedermann, MD, Department of Dermatology and Allergy Biederstein, Technical University of Munich, a team of investigators aimed to identify clinical criteria in patients with PEG allergy and compare with criteria reported in previous literature before applying these criteria to real-life patients who requested an allergy workup for COVID-19 vaccine hypersensitivity.
Between 2006 and 2019, investigators recruited patients with immediate-type allergic reactions to PEG.
Medical charts for each patient were retrieved from 2 large allergy unites in Southern Germany with clinical data including history and skin prick (SPT) testing, intradermal (IDT) and oral provocation tests (OPT).
Patients referred to an allergy unit from April 2020 until April 2021 due to self-reported adverse reactions from the first dose of a mRNA or DNA COVID-19 vaccine or reporting a possible allergy against a vaccine ingredient were assessed ad managed prospectively.
Testing was conducted with vaccines, PEG, PS80, and trometamol, and patients with no clinical criteria for PEG allergy were vaccination without allergy tests.
Outcomes of vaccinations were recorded by patient interviews that detailed hypersensitivity reactions and asked for events that occurred within 1 hour of the vaccination.
A total of 421 prospective real-life patients asking for allergy workup for COVID-19 vaccine hypersensitivity were featured in the study.
According to investigators, 10 patients with confirmed IgE-mediated allergic reactions to PEG were identified in the 2 allergy unites featured in the study.
The report included the highest number of allergy-tested PEG allergic patients in allergy-based literature, though the study (which spanned 14 years) showed that PEG allergies were rare.
Additional, reports of repeated reactions were frequent (40%), but not seen in a majority of patients.
Of the 10 patients with PEG allergy, all 10 had skin tests ± BAT with PEG ± elicitors which were positive, and provocation tests were positive in 7 out of 9 patients.
For those in the prospective cohort, 52 patients were tested with 3 (6%) had identified PEG allergy.
Vaccination was recommended in all these patients, with no hypersensitivity reactions reported to vaccination including these 6 PEG-allergic patients who tolerated the COVID-19 vaccine.
The investigators added that their study “demonstrated the value of allergy tests for detecting PEG allergy, and safely vaccinated all patients, including those with PEG allergy with a DNA vaccine, by giving specific individual recommendations for the vaccination approach according to risk analysis and with shared decision making.”
The study, “Experience with polyethylene glycol allergy-guided risk management for COVID-19 vaccine anaphylaxis,” was published online in the European Journal of Allergy and Clinical Immunology.