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At least six people have had serious allergic reactions to Pfizer’s COVID-19 vaccine, prompting the CDC to issue some cautionary guidelines. SOPA Images/Getty Images
  • Six people in the United States have experienced severe allergic reactions (anaphylaxis) after receiving the COVID-19 vaccine.
  • Experts say anaphylaxis is rare, but those who’ve had serious reactions to vaccines or injectable medicines in the past should talk with their doctor and be monitored for 30 minutes after getting the shot.
  • Those who are seriously allergic to any of the ingredients included in the shots should skip the vaccine, the CDC recommends.
  • In general, the benefits of the vaccine far outweigh the rare risks, experts say.

The Centers for Disease Control and Prevention (CDC) released new guidelines this past weekend advising people in the United States who are severely allergic to the ingredients in the COVID-19 vaccines to not get the inoculation.

The guidelines come after at least six adults experienced a significant allergic reaction, called anaphylaxis, after getting the vaccine.

The reactions, which included elevated heart rate, shortness of breath, and lightheadedness, occurred within 30 minutes of vaccination. In Alaska, two healthcare workers developed symptoms within 10 minutes of being inoculated.

Severe reactions to COVID-19 vaccines appear to be isolated with only a small handful of serious reactions occurring out of the hundreds of thousands of people who’ve been vaccinated in the United States.

The CDC recommends all adults be monitored for 15 minutes after getting vaccinated. People with a history of severe allergic reactions should be observed for 30 minutes in a medical facility that can provide quick treatment if an adverse event occurs.

The CDC is advising that people who have a history of allergic reactions to any of the ingredients included in the shots talk with their doctor before getting vaccinated.

The full list of ingredients — which include sodium chloride, potassium chloride, and a number of lipids — can be found on the Pfizer vaccine’s prescribing information chart.

Moderna’s vaccine prescribing information chart also lists the ingredients, which include various lipids, sodium acetate, and tromethamine.

Another ingredient in question is polyethylene glycol, a laxative commonly used with colonoscopies. Few cases of anaphylactic reaction have been linked to polyethylene glycol, but the reaction has been reported in the past.

The Moderna and Pfizer vaccines don’t include preservatives, and the vial stoppers are not made with latex.

People who’ve had a serious allergic reaction to any injectable medicine or vaccine in the past should consult their doctor.

These individuals can still get the vaccine, but they’ll be monitored for a longer period of time, according to Dr. William Schaffner, an infectious disease expert at Vanderbilt University in Tennessee.

Those with other allergies not related to vaccines — including “allergies to food, pet, venom, environmental, or latex” — should still get vaccinated, the CDC recommends.

“They can get their vaccine, and we’ll watch them for 15 minutes,” Schaffner told Healthline.

You should still plan to get vaccinated if:

  • You’ve had a serious allergic reaction to oral medications.
  • You have a family history of severe allergic reactions to vaccines.
  • You’ve had mild reactions to vaccines.

Dr. Henry Bernstein, a pediatrician at Northwell Health’s Cohen Children’s Medical Center and a member of the CDC Advisory Committee on Immunization Practices (ACIP), said the CDC and the Food and Drug Administration (FDA) are closely monitoring reactions to the vaccine.

“Safety is being closely monitored as always with all vaccines, and especially now with the COVID-19 vaccines,” Bernstein told Healthline.

The system is working, Schaffner said.

The cases are under careful investigation to determine the nature of these problems, Schaffner noted.

“It’s still very early days, but we know it’s very unusual,” Schaffner said.

In clinical trials, Pfizer found that less than 1 percent of more than 22,000 people who received the vaccine experienced possible allergic reactions.

No cases of anaphylaxis were recorded in the trials, but a small portion of trial participants experienced “hypersensitivity-related adverse events.”

It’s known that these shots can cause more local reactions similar to the flu shot, Schaffner said. They can make your arm sore, and cause fatigue, headache, or fever.

“That’s actually the immune system working on the vaccine,” Schaffner said.

As of Monday, Dec. 21, six cases of severe allergic reactions have been reported in the United States out of the hundreds of thousands of people who’ve been vaccinated.

All of the people who experienced those reactions recovered smoothly after being treated with a combination of epinephrine, Pepcid, and Benadryl.

Bernstein said the benefits of the vaccine far outweigh the rare risks.

“Getting COVID is, in my opinion, much more of a concern than the risk of having a severe allergic reaction to the vaccine. No question about it,” Bernstein said.

Healthcare providers are well trained and counseled on how to treat these types of reactions. COVID-19, however, continues to be an unpredictable and potentially life-threatening disease for certain people.

“It’s one of those risk-benefit calculations that’s so difficult,” Schaffner said. “If they’re older, if they have a number of chronic underlying conditions, they’re at serious risk of COVID, and these allergic reactions have been very rare.”

Health experts aren’t surprised this vaccine has triggered serious allergic reactions in a handful of people, as allergic reactions can happen with any vaccine.

“We’re always aware that such a reaction can happen with any vaccine,” Bernstein said. “This is something we are familiar with, comfortable with handling, and people should know all the sites that are administering the vaccine are readily prepared should an adverse reaction happen.”

The people who experienced severe reaction to the vaccine reported a range of symptoms, including:

  • elevated heart rate
  • rash
  • eye puffiness
  • lightheadedness
  • scratchy throat

Most of the serious reactions have occurred within 15 to 30 minutes.

Schaffner said this is why people with a history of serious reactions to vaccines will be monitored for 30 minutes after getting the COVID-19 shot.

It’s crucial for vaccination sites to be prepared to handle an allergic reaction, according to Bernstein.

This includes having epinephrine, and the ability to take vital signs like blood pressure and oxygen levels, Bernstein noted.

The CDC also states that those who have a severe reaction to the first shot should not receive the second shot, which is typically given 3 to 4 weeks after the first dose.

If you have a history of allergic reactions or if you’re concerned you might have one with the COVID-19 vaccine, talk with your doctor.

Doctors can review your medical history, and help you understand your risks and benefits when it comes to getting inoculated against COVID-19.