Can the COVID-19 vaccine cause an allergic reaction?
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Can The Covid-19 Vaccine Cause Allergic Reactions?

Physicians weigh in about the possible reactions in children and adults.

by Lindsay E. Mack
Originally Published: 

The COVID-19 vaccine rollout is a huge win in the battle against coronavirus, but plenty of people have questions about this injection. For instance, does the COVID-19 vaccine cause allergic reactions in adults or children? Here's what two physicians familiar with the vaccine had to say.

"The available vaccines are both pretty basic; there aren't a whole lot of ingredients such as preservatives or adjuvants to stimulate your immune system, in either," as Dr. Chad Sanborn, MD, of KIDZ Medical Services tells Romper via email. "So, yes, these vaccines could cause allergic reactions in adults and children, however, we do not think they will, at least not in large numbers." Although the potential for an allergic reaction may sound alarming, both physicians stressed the relative rarity of these reactions, as well as the overall efficacy of the vaccine. "There have been over 18 million cases of COVID-19 and over 300,000 deaths. By getting the vaccine, you are not only protecting yourself, but your loved ones as well," as Dr. Kristina Scanlan, D.O., who specializes in family practice as well as palliative care, tells Romper via email. "The COVID-19 vaccine is both safe and effective." Here's a more in-depth look at what's in the COVID-19 vaccine, including potential allergens, as well as more info about how medical professionals help monitor everyone for adverse reactions.


What Can Cause An Allergic Reaction To The COVID Vaccine?

"Investigations are ongoing with what triggers severe allergic reactions in some people who have had the COVID-19 vaccine. However, the culprit is suspected to be polyethylene glycol," says Dr. Scanlan. A common ingredient in healthcare, polyethylene glycol appears in everything from injectable steroids to laxatives, as Dr. Scanlan explains. In some very rare cases, ingesting or getting injected with polyethylene glycol can cause severe allergic reactions in some people.

In addition, people who have had allergic reactions to the flu vaccine can likely get the COVID-19 vaccine without issue. "If you are allergic to the flu shot, it does not mean that you will be allergic to the COVID-19 vaccine. Pfizer’s COVID-19 vaccine lacks preservatives and egg proteins found in the flu shot," says Dr. Scanlan. Definitely discuss any known allergies with your physician before getting the COVID-19 vaccine, however.

What Does An Allergic Reaction To A Vaccine Look Like?

Sometimes allergic reactions are relatively mild. "Minor signs of an allergic reaction to a vaccine would include a rash, such as hives, especially a local one," says Dr. Sanborn. "Those are generally not considered severe, and if you had a minor rash with an injectable vaccine in the past that would NOT be a contraindication to the COVID vaccine."

But sometimes more serious reactions do occur. "In some people, allergens can cause severe allergic reactions called anaphylaxis," says Dr. Scanlan. "Anaphylaxis occurs when someone comes into contact with an allergen and their immune system has an extreme response. This exposure can be life threatening and leads to tongue or throat swelling that affects breathing. Anaphylaxis can also cause hives, nausea, vomiting, and a fast heart rate. It typically occurs within second to hours after exposure." In these instances, epinephrine (the active ingredient in the EpiPen) is given to help ease the symptoms, as Dr. Scanlan further explains.

How Do Medical Professionals Help Monitor For Allergic Reactions?

"After receiving the vaccine, the CDC recommends waiting 15 minutes to make sure that you don’t develop an allergic reaction," says Dr. Scanlan, who adds that any reactions tend to occur within minutes of receiving the injection. "If you have a history of anaphylaxis in the past, the waiting period is 30 minutes. The staff are trained in how to manage severe allergic reactions and can react promptly." If you're at all concerned about the possibility of a severe allergic reaction, alert the medical professionals beforehand and plan to hang out for a bit after the injection.

How Many People Have Had Allergic Reactions To The COVID Vaccine?

Information about allergic reactions to the vaccine is being closely monitored. "The CDC has recorded 6 cases of anaphylaxis as of 12/18/20 out of the 272,001 vaccinations given. In all of these cases, they occurred during the waiting period after receiving the injection," says Dr. Scanlan. In general, this vaccine and its effects are being closely monitored. "I would like people to understand that these vaccines should be considered safe, and the fact that they are new does not imply that we are being careless with their development or administration; in fact, we are monitoring for side effects more closely than ever before," says Dr. Sanborn.

Children: Babies, Kids, Tweens, and Teens

The COVID-19 vaccine is not yet available for people ages 15 and younger, although information about the potential rollout time for a children's COVID-19 vaccine is under study, per Connecticut Children’s. At this time, information about the vaccine's potential for an allergic reaction in babies and children is still being gathered. "The Pfizer COVID-19 vaccine has been approved for use in children ages 16 and older as well as adults. The Moderna COVID-19 vaccine is approved in ages 18 and older. It has not been studied in babies or children younger than 16," says Dr. Scanlan. "In the future, it will likely be studied in those age groups." For the most part, physicians are positive about the potential for vaccinating the younger set soon. "Of course, we are cautious about and take seriously all medications and vaccines given to infants, but again there is no reason to think that they will get more allergic reactions than older kids or adults from these COVID vaccines," says Dr. Sanborn.

In general, physicians don't want the (relatively minor) possibility of an allergic reaction to stop people from getting the COVID-19 vaccine. "I absolutely do not want people to become terrified of these vaccines based upon news stories emphasizing these reactions," says Dr. Sanborn. "These reactions have only happened in a handful of cases out of hundreds of thousands of vaccine doses administered worldwide, and the vaccines are being monitored more closely than most other vaccines because of the massive rollout for millions and millions of people simultaneously." For the vast majority of people, getting the vaccine is a fantastic way to protect yourself and your loved ones from COVID-19 and help bring the pandemic to an end.

Experts sourced

Dr. Chad Sanborn, MD, of KIDZ Medical Services

Dr. Kristina Scanlan, D.O., who specializes in family practice as well as palliative care

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