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  • The risk of getting an allergic reaction is a concern for people who are about to receive the vaccine.
  • A small number of people have experienced an allergic reaction shortly after their first dose.
  • Experts say the risk of an allergic reaction is very rare and that when it does occur, it’s easily treated.

Widespread distribution of effective COVID-19 vaccines is bringing a nationwide sigh of relief that we might finally put this pandemic behind us.

But there’s a concern among some about getting the shot: the risk of an allergic reaction.

A small number of people have experienced an allergic reaction soon after receiving their first dose of the COVID-19 vaccine.

But the risk is low: only about 1 in 100,000 people experience an allergic reaction after getting the injection.

We talked to experts about how healthcare providers are prepared for these rare events.

A Food and Drug Administration (FDA) emergency use authorization has been issued for two vaccines so far. They are:

  • Pfizer-BioNTech. This vaccine is recommended for people 16 years and older, and is 95 percent effective at preventing illness.
  • Moderna-NIAID. This vaccine is recommended for those 18 years and older, and is 94.1 percent effective.

Joan Kapusnik-Uner, PharmD, vice president of clinical content at First Databank (FDB), which publishes and maintains drug and medical device databases for healthcare professionals, said it’s important to know that there may be slight side effects from the vaccine that aren’t problematic.

“COVID-19 vaccines are administered with the intent of triggering the immune system and therefore can cause generalized symptoms for several days,” she said, “including fever, malaise, and fatigue while they are also working to mount their efficacious durable immunity via antibody production, and B cell & T cell responses.”

Kapusnik-Uner emphasized that true allergic reactions are rare, and may include rash or itching.

According to the Centers for Disease Control and Prevention (CDC), the vaccine adverse event reporting system (VAERS) detected 10 cases of anaphylaxis (severe allergic reaction) after administration of a little over 4 million first doses of the Moderna vaccine. In nine of them, onset occurred within 15 minutes of vaccination, with no anaphylaxis-related deaths reported.

“In a recent study in JAMA [The Journal of the American Medical Association], the incidence of anaphylaxis or severe allergic reactions after the Pfizer vaccine was rare, affecting just 11 people per million,” said Dr. Robert Glatter, an emergency physician at Lenox Hill Hospital in New York. “The majority of these reactions developed within 15 minutes.”

Symptoms of this severe reaction include:

  • hives
  • rash
  • lip or tongue swelling
  • throat swelling

“It is uncommon to be allergic to the vaccine,” said Theresa Capriotti, DO, MSN, RN, clinical nursing professor at Villanova University’s M Louise Fitzpatrick College of Nursing. “The most severe type of allergic reaction is anaphylaxis.”

But this allergic reaction is easily treated.

“Patients would have to sit for 15 minutes usually, after injection. There is treatment for allergic reaction so individuals should not fear it,” Capriotti said. “They would be given an epinephrine injection, also Benadryl injection. They could even be given prednisone if needed.”

According to Capriotti, those most at risk for a reaction would be anyone allergic to the vaccine’s ingredients. She also said the healthcare provider administering the vaccine will ask you a set of questions prior to giving you the shot.

Dr. Steven Quay, PhD, CEO of Atossa Therapeutics, a clinical stage biopharmaceutical company developing therapeutics for breast cancer and COVID-19, said that it’s all about language, and all adverse events are things that shouldn’t happen and have some medical impact.

“An allergic reaction is one of the adverse reactions, so it’s a kind of adverse reaction that falls on a spectrum of different kinds,” he said.

According to Quay, allergic reactions are the body’s response to histamine.

“So what does histamine do? Histamine can give you hives (little spots that make your skin itchy), it can constrict your throat, it can constrict the bronchi in your lungs, making it difficult to breathe,” he said.

However, with currently available vaccines, this reaction is still uncommon.

Quay advised that before getting your first COVID-19 vaccination, ask the doctor or nurse, “Where is your EpiPen, where is your epinephrine kit?”

Because if you start to have a reaction, “things happen really fast, minutes go by and it can get very, very serious. You don’t want them in another room running around to find the EpiPen,” he said.

Quay stressed that a severe reaction is still very, very rare.

“It happens about one in a million with most vaccines,” Quay said. “So far with the two mRNA vaccines, it’s about 10 times more; so about 1 in a 100,000. But so far they’ve been treated, no one’s died. You don’t want to have it, but it has been treated.”

“The risk specific to mRNA vaccines is related to polyethylene glycol (PEG), which is part of the lipopolysaccharide coating which is used to encapsulate the mRNA particle,” Glatter said. “This also applies to polysorbate, which is not in the mRNA COVID-19 vaccines, but is closely related to PEG.”

Glatter said that if you know you’re allergic to an ingredient in the vaccine, you should talk with an allergist before receiving the shot.

“In addition, if you have already had a reaction to the first dose of the vaccine, then a visit to an allergist is a good idea before considering the second dose,” he said.

According to Glatter, the people at higher risk for an allergic reaction include those who have previously experienced anaphylaxis from:

  • drugs
  • medical products
  • foods
  • insect stings

With millions already vaccinated with the new COVID-19 vaccine, people are worried about experiencing an allergic reaction, especially one called anaphylaxis.

Experts say the rate of allergic reactions to a vaccine dose are very rare, but when they do occur, they’re easily treated.

Experts recommend asking your vaccine administrator if they have treatment options (like EpiPens) readily available and to sit for 15 minutes after getting the shot in case you do experience an allergic reaction.