Polyethylene glycol (PEG) is a cause of anaphylaxis to the Pfizer/BioNTech mRNA COVID‐19 vaccine

Abstract

Common drugsCommon drugs containing PEG: laxatives, Gaviscon double action, depotcorticosteroids, for example methylprednisolone, Depo Provera, penicillin Importance of brand Depends on brand (checklist of excipients 6.1 on SmPC or contents 6 on PIL). PEG is also called macrogol PEG Molecular Weight Higher PEG MWs appear more allergenic, and molecular weight and amount of PEG determines whether an allergic reaction occurs Topical products Mild usually cutaneous reactions (pruritus, rhino-conjunctivitis) to cosmetics, toothpaste, mouthwashes, shower gels, moisturizers, hand sanitizers and soaps often with lower PEG molecular weights. Vaccine reaction Immediate-onset (minutes) severe systemic allergic reaction to an mRNA COVID−19 vaccine Abbreviations: MW, molecular weight; PEG, polyethylene glycol; SmPC, summary of product characteristics. TA B L E 1 The clinical features of a PEG-allergic patient may help identify at-risk patients before vaccination or if a COVID-19 vaccine reaction was likely due to PEG Key messages 1. The Pfizer/BioNTech COVID-19 vaccine can cause severe anaphylaxis of unknown cause 2. Here, we show polyethylene glycol allergy caused one of the first cases of anaphylaxis to the Pfizer/BioNTech COVID-19 vaccine 3. Allergy skin prick testing with polyethylene glycol triggered anaphylaxis, highlighting the importance of safety procedures during investigation | 863 RESEARCH LETTER

Adverse reactions to COVID‐19 vaccines: A practical approach

“…So far only a single case of confirmed IgE mediated allergy to PEG in the Pfizer vaccine has been reported. 7 As we gain more insight into potential mechanisms of hypersensitivity reactions to these vaccines, non-IgE mechanisms might become more relevant.…”

“…26 There is only a single report of confirmed PEG allergy in a patient with a history of anaphylaxis to the Pfizer vaccine. 7 Other mechanisms might also be relevant. IgG and IgM anti-PEG antibodies have been detected in up to 50% of healthy individuals.…”

Adverse rare events to vaccines for COVID-19: From hypersensitivity reactions to thrombosis and thrombocytopenia

“…Some components of the vaccines for COVID-19 have been pointed out as the possible responsible(s) of the hypersensitivity reactions, due to scientific data on their potential as allergenic compounds. In that sense, some of the excipients contained in the mRNA and DNA vaccines have been previously involved in hypersensitivity allergic reactions and some studies are beginning to analyze their possible role in the reactions to the COVID-19 vaccines ([ 37 , 49 ]. Excipients such as PEG contained in the mRNA vaccines BNT162b2 and mRNA-1273 as part of the PEGylated LNP has been previously described as a compound with the potential to induce severe allergic reactions.…”

“…Interestingly, the patient had a history of drug allergy and she was previously sensitized to PEG, although she was unaware of her PEG allergy, possibly due to a misdiagnosis of the specific excipient to which she was allergic to. The diagnosis of PEG allergy is usually difficult to establish due to the widespread use of PEG and its presence in multiple drugs and cosmetic products [ 37 ]. Despite this fact, a current revision of FDA data has found an average of four anaphylactic reactions to PEG per year in individuals exposed to PEG-containing drugs for colonoscopy or laxatives [ 38 ].…”

Vaccine allergy: evidence to consider for COVID-19 vaccines

“…However, polyethylene glycol (PEG, in mRNA vaccines) and its derivatives including polysorbate 80 (in viral vector vaccines) have been suggested as potential culprit allergens (Table 1 ), possibly leading to more frequent anaphylactic reactions than to vaccines against other infectious diseases [ 22 ▪ , 23 ▪ ]. Recently, a group from the United Kingdom demonstrated PEG allergy in one of the first cases developing anaphylaxis to the Pfizer/BioNTech COVID-19 vaccine in the United Kingdom [ 24 ▪▪ ]. The patient had a previous history of anaphylaxis to other medication and milder reactions on exposure to other products suggestive of an undiagnosed PEG allergy.…”