Pfizer vaccine triggers rare adverse reactions, the "culprit" is polyethylene glycol?

Severe allergic reactions also occurred in the United States after the Emergency Vaccination against COVID-19 in the United Kingdom. This has caught the attention of scientists, what exactly is the ingredient that triggers the allergic reaction?

According to a new report released by Thomas Clark of the Centers for Disease Control and Prevention (CDC), as of Dec. 19, 272,001 people in the U.S. have been vaccinated against COVID-19, including six cases of allergic reactions. In the United Kingdom, on December 8, local time, two medical staff developed a serious allergic reaction after receiving the same Pfizer new crown vaccine. In response, the British drug regulator then issued a warning to remind people with a history of severe allergies that they should not be vaccinated with this new crown vaccine, and also launched an investigation into the incident.

Elizabeth Phillips, a drug allergy researcher at Vanderbilt University Medical Center, said that because the Pfizer and Moderna mrna vaccines use a new platform, the triggered allergic reactions need to be carefully reviewed.

On December 21, officials at the National Institute of Allergy and Infectious Diseases (NIAID) said the United States was prepared to study the phenomenon of severe allergic reactions in some people after receiving the Pfizer COVID-19 vaccine.

What exactly caused the allergic reaction of the Pfizer covid-19 vaccine, although a scientific conclusion has not yet been given, but many experts have focused on the nanoparticles of the messenger RNA delivery system, which contain polyethylene glycol.

On December 21, Science published an article saying it suspected nanoparticles in Pfizer's COVID-19 vaccine would trigger rare allergic reactions, the compound polyethylene glycol. In the past two weeks, at least 8 people have had a severe allergic reaction after receiving the COVID-19 vaccine produced by Pfizer and Biontech.

Polyethylene glycol is a compound whose series of products is non-irritating, slightly bitter in taste, has good water solubility, and has good compatibility with many organic components. They have excellent lubricity, moisturizing, dispersing, adhesive, can be used as antistatic agents and softeners, etc., in cosmetics, pharmaceuticals, chemical fiber, rubber, plastics, paper, paints, electroplating, pesticides, metal processing and food processing and other industries have a very wide range of applications.

"PEG Has a stabilizing effect, increasing the stability and shelf life of the vaccine. However, polyethylene glycol is the first time it has been used in a human vaccine, and it is known that it can cause life-threatening allergic reactions such as difficulty breathing, rapid drop in blood pressure, and rapid heartbeat. A virologist said.

Polyethylene glycol has never been used in approved vaccines, but is present in many drugs that trigger allergic reactions, a potentially life-threatening reaction. Can cause a rash, a sharp drop in blood pressure, shortness of breath and rapid heartbeat. Some allergists and immunologists believe that a small number of people who have previously been exposed to PEG may have high levels of PEG antibodies, putting them at risk of allergic reactions when using the vaccine.

Both vaccines produced by Pfizer and Moderna use lipid nanoparticles to wrap the vaccine components in them, which help carry the vaccine components into human cells and also act as adjuvants, which are vaccine components that enhance the immune response.

In response to this possibility, Alkis Togias, head of the Niaid Allergy, Asthma and Respiratory Biology branch, told the media on Monday that the study is still in the early planning stages and that the study is expected to include "hundreds" of people who have had a history of severe allergic reactions. His department will lead the study, and the researchers hope to begin the study in a matter of weeks, but the exact timing is uncertain. While only people vaccinated with the Pfizer vaccine have reported these reactions so far, this study may look at both the vaccines produced by Pfizer and Moderna.

Polyethylene glycol has long been thought to be biologically inert, but there is growing evidence that this is not the case. According to a 2016 study led by Samuel Lai, a pharmacological engineer at the University of North Carolina at Chapel Hill, as many as 72 percent have antibodies against polyethylene glycol, which may be due to exposure to cosmetics and drugs. He found that about 7 percent of people's antibody levels may be high enough to induce allergic reactions, and other studies have also found antibodies against polyethylene glycol, but at lower levels.

Finding the culprits of allergic reactions will be an important piece of work for the National Institute of Allergy and Infectious Diseases in the coming weeks.