CLEVELAND, Ohio — You’ve decided you’d prefer to get Moderna’s coronavirus vaccine instead of the one made by Pfizer/BioNTech. Can you make a specific request to get one or the other?
Our readers have questions about the coronavirus vaccine, and cleveland.com is getting answers from health care experts.
Q. Could I request one COVID-19 vaccine if I’m allergic to an ingredient in the other?
Generally speaking, there’s little reason to make a specific request for one of the two COVID-19 vaccines that have been approved for use in the U.S., experts say. They’re very similar.
Allergic reactions to the COVID-19 vaccine can occur, but they are rare, according to the U.S. Centers for Disease Control and Prevention. The Pfizer/BioNTech and Moderna vaccines that have been approved for use in the U.S. do not contain eggs, preservatives or latex.
“This vaccine doesn’t have some of the ingredients that we know are associated with allergic reaction,” said Dr. David Lang, chairman of the department of allergy and clinical immunology at the Cleveland Clinic.
There is one small exception. Some people can develop an allergy to the polyethylene glycol contained in both vaccines, but it’s not common, Lang said. The ingredient, also known as PEG, is the basis for laxatives such as MiraLAX. Only those patients with a known allergy to polyethylene glycol should not get the vaccine, Lang said.
A CDC study found only 21 of more than 1.8 million shots of the Pfizer vaccine resulted in anaphylaxis. Another CDC study found only 10 of more than 4.4 million doses of the Moderna vaccine resulted in anaphylaxis.
Both vaccines are made with messenger RNA, which teaches the body to make a harmless part of the spike protein that is found on the coronavirus. That induces an immune response that protects against the virus that causes COVID-19.
The Pfizer vaccine’s ingredients also include lipids (including PEG), potassium chloride, monobasic potassium, phosphate, sodium chloride, dibasic sodium phosphate dihydrate and sucrose.
The Moderna vaccine’s ingredients also include lipids (including PEG), tromethamine, tromethamine hydrochloride, acetic acid, sodium acetate and sucrose.
The primary issue with requesting one vaccine instead of the other is that providers don’t get to choose which vaccine they get in a shipment. If you pass up your chance to get the Pfizer vaccine, there’s no telling when you might be able to get the Moderna vaccine, or vice versa, experts said.
“Whatever the state sends me is what I’m using to vaccinate right now,” said Jodie Turosky, the clinical director of the pharmacy at Cleveland’s St. Vincent Charity Medical Center. “Yes, you may request something specific. But it may cost you your seat at the vaccine table.”
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