Polyethylene Glycol - The Prize in Every Vial of COVID-19 Vaccine

While it may not appear terribly topical, research from 2013 - 2014 by Johans Verhoef and Thomas Anchordoquy entitled "Questioning the Use of PEGylation for Drug Delivery" as shown here:

 

...may cause some concern for those being vaccinated against COVID-19 by either the Moderna or the Pfizer vaccine since polyethylene glycol has never before been approved for a vaccine.

 

Here is the abstract from the article:

 

"Polyethylene glycol (PEG) is widely utilized in drug delivery and nanotechnology due to its reported “stealth” properties and biocompatibility. It is generally thought that PEGylation allows particulate delivery systems and biomaterials to evade the immune system and thereby prolong circulation lifetimes. However, numerous studies over the past decade have demonstrated that PEGylation causes significant reductions in drug delivery, including enhanced serum protein binding, reduced uptake by target cells, and the elicitation of an immune response that facilitates clearance in vivo. This report reviews some of the extensive literature documenting the detrimental effects of PEGylation, and thereby questions the wisdom behind employing this strategy in drug development."

 

As background, polyethylene glycol (PEG) is a water-soluble, hydrophilic molecule petroleum-derived compound made from ethylene glycol (which you may know best as the main ingredient in antifreeze).  It is found in a significant number of products including skin creams, toothpastes, personal lubricants, food additives, cosmeticslaxatives and, when attached to various protein medications, will allow for slower clearing of the protein from the blood.  It also has a significant number of industrial uses. 

 

There is a downside to PEG that are of significant concern.  Recent research by Priya Sellaturay et al in the Journal of Allergy and Clinical Immunology: In Practice as well as the National Institutes of Health website as shown here:

 

...demonstrates that certain individuals can have severe allergic reactions to PEG including near-fatal anaphylaxis.

 

This is not the only study to note this issue.  A 2019 study by Vicente Jover Cerda et al notes that several anaphylactic reactions can occur in people who are hypersensitive to pharmacological and cosmetic products that contain PEG as shown here:

Here is a link to another study on PEG as a cause of anaphylaxis from 2016 which found that 72 percent of contemporary human blood samples contained anti-PEG antibodies, up from 56 percent of samples from the 1970s to 1990s with the potential for hypersensitive or anaphylactic reactions , likely a result of increased exposure to polyethylene glycol in cosmetics and pharmaceuticals:

 

...and an article from December 2019 on the Physician's Weekly website (original link here) from research done by Cosby Stone et al as shown here:

 

From the research on PEG, some researchers suggest that allergies to certain pharmaceuticals may not be related to the active ingredients in the drugs, rather the reaction could be due to the presence of polyethylene glycol, a commonly used ingredient in pharmaceuticals.

  

Now, with this information in mind, let's look at the contents of the Pfizer/BioNTech and Moderna COVID-19 vaccines from information released by the United States Food and Drug Administration as part of its Emergency Use Approval process: 

 

1.) Pfizer/BioNTech vaccine: 

 

2.) Moderna vaccine: 

 

As you can see, Just like Cracker Jacks, there's a prize in every package (vial)!  In these two vaccines, the mRNA is wrapped in lipid nanoparticles that help carry the mRNA to human cells.  These lipid nanoparticles are "PEGylated" or chemically attached to polyethylene glycol molecules that coat the exterior of the particles, allowing for a longer life span to improve absorption.

 

Given the growing number of anaphylactic responses to COVID-19 vaccines given the relatively low penetration rate of the vaccines into the general population and the possibility that one of the inactive ingredients in the vaccines may be responsible, it will be interesting to see how many more severe allergic reactions occur as hundreds of millions of people around the world receive their "jab", particularly as the second dose of vaccine is administered.