Like Pfizer’s, Moderna’s vaccine is designed around a molecule called messenger RNA (mRNA), which is injected into the upper arm. Once inside the human cell, the mRNA will direct the production of a protein called spike, which then teaches the immune system to recognize and stop the coronavirus, as long as it has invaded the body. Each vaccine contains a small amount of other ingredients that wrap the fragile mRNA in a protective greasy foam and help stabilize the formulation during transportation.
None of the ingredients in the two vaccines have been identified as common allergens. However, several experts are careful to point out that although the formula is slightly different, the polyethylene glycol or PEG that appears in both formulas may be the culprit. PEG is found in a range of medicines, including ultrasound gels, laxatives, and injectable steroids, and allergies to it are extremely rare.
Dr. Kimberly Blumenthal (Dr. Kimberly Blumenthal), an allergist and immunologist at Massachusetts General Hospital, pointed out that if there is no blood work to find an enzyme called trypsin that is released during an allergic reaction, it is sometimes very It is difficult to determine allergic reactions. She added that it is crucial to have proper agreements so that similar cases can be further investigated.
According to data files from its later clinical trials, Moderna did not report any link between its vaccine and allergic reactions. However, when the product develops from closely monitored research to widespread distribution, rare side effects occur.
The recent allergic reactions related to vaccines that are very similar to Pfizer prompted heated discussions between the FDA and CDC in an advisory group discussion held this month. Experts pointed out that allergic reactions appeared to occur at an unusual frequency and were quickly distributed. . (Under normal circumstances, people’s allergic reactions to vaccines are thought to occur at a rate of one in a million.)
Denise Grady and Noah Weiland contributed reports.