New Insights on Cause of Anaphylaxis Following COVID-19 Vaccination - BSACI

New Insights on Cause of Anaphylaxis Following COVID-19 Vaccination

The severe allergic reactions after COVID-19 vaccination raised important questions for the whole immunization programme. This new finding, confirming the suspicion that PEG may be a cause of anaphylaxis, represents an important step forward in our understanding, and knowing its rarity, offers further reassurance regarding the safety of the programme. 

Adam Fox, BSACI President


Please see below a press release from Wiley Blackwell

On the first day of the UK campaign for COVID-19 vaccination, there were reports of two cases of anaphylaxis—a severe, potentially life-threatening allergic reaction—within minutes of administration of the Pfizer/BioNTech mRNA vaccine. Subsequently further cases of suspected anaphylaxis to the Pfizer vaccine were reported. A new report published in Clinical & Experimental Allergy reveals that an allergy to the ingredient polyethylene glycol (PEG) is a cause of anaphylaxis to the vaccine. However, this is in the context of millions of doses safely administered.

The authors note that very few people are allergic to PEG, and they provide a guide to identifying those who are at risk. “This preliminary report confirms PEG as a cause of anaphylaxis to the Pfizer/BioNTech vaccine, for the first time,” they wrote. “COVID-19 vaccine anaphylaxis and PEG allergy are both rare, so proof of PEG as the cause in one case of vaccine anaphylaxis is important. However, it is important to emphasise that PEG allergy is rare and that COVID-19 vaccines remain safe.”

Additional Information

Link to Study

About the Clinical & Experimental Allergy Journal

Clinical & Experimental Allergy is the Official Journal of the British Society for Allergy & Clinical Immunology, publishing clinical and experimental observations in disease in all fields of medicine in which allergic hypersensitivity plays a part. Clinical & Experimental Allergy strikes an excellent balance between clinical and scientific articles and carries regular reviews and editorials written by leading authorities in their field.

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