Read the original article on Best Life. The CDC’s guidelines note that “an allergic reaction is considered severe when a person needs to be treated with epinephrine or EpiPen or if they must go to the hospital.” And for more vaccine warnings, check out Will the New COVID Strain Make the Vaccine Useless? Experts Weigh In. The CDC explains that those known to have adverse reactions to foods, pets, latex, or environmental conditions could still get vaccinated as normal. Those with allergies to oral medication or who have a wider family history of allergic reactions are also in the clear. However, anyone with a known history of severe allergic reactions to vaccines should speak to their doctor before going ahead with the COVID-19 shot. And for more on signs you might have had the virus, check out These 2 Strange Symptoms Could Mean You’ve Already Had COVID. The CDC’s update follows reports of five allergic reactions among patients who had had been administered the Pfizer-BioNTech vaccine in the U.S. These incidents are currently being investigated by the U.S. Food and Drug Administration (FDA), Reuters reports, but those affected by these adverse reactions have recovered. And for more up-to-date news on COVID delivered right to your inbox, sign up for our daily newsletter.ae0fcc31ae342fd3a1346ebb1f342fcb It’s currently unclear, but Science magazine reports that the allergic response “may be due to a compound in the packaging of the messenger RNA (mRNA) that forms the vaccine’s main ingredient.” The Moderna vaccine also contains the compound, polyethylene glycol (PEG). While PEG has not been used previously in vaccines, it is commonly found in drugs that have occasionally caused anaphylaxis (it is also regularly used in everyday products such as toothpaste and shampoo). However, at this point, this is just a theory: “Until we know there is truly a PEG story, we need to be very careful in talking about that as a done deal,” Alkis Togias, MD, branch chief of Allergy, Asthma and Airway Biology at the National Institute of Allergy and Infectious Diseases (NIAID), told Science. And for more on the latest vaccine news, check out If You’re Allergic to This, You Should Wait to Get the COVID Vaccine.