What’s in the COVID vaccine? Doctors assure allergy-sufferers it’s OK to get the shot
With more than 4.5 million Americans injected with their first dose of one of the two available COVID-19 vaccines, allergic reactions continue to prove rare across the nation.
As of Dec. 31, there were at least 10 reported cases of allergic reactions to the Pfizer-BioNTech vaccine and two cases to the Moderna shot, according to a team of allergists led by doctors at Massachusetts General Hospital.
Allergic reactions to vaccines are rare, the team said, and generally occur at a rate of 1.3 per 1 million people.
The small number of individuals also all experienced allergic reactions within the recommended 15- to 10-minute observation period following COVID-19 vaccination and were quickly resolved of all their symptoms, the team said in their article published last week in The Journal of Allergy and Clinical Immunology: In Practice.
To date, no deaths or long-term consequences have been reported following allergic reactions to any of the COVID-19 vaccines.
That’s why the team of allergists says people with a history of food or medication allergies can safely receive a coronavirus vaccine, especially since both options do not contain any foods such as eggs, drugs, preservatives or latex — all common allergens.
“As allergists, we want to encourage vaccination by reassuring the public that both [FDA-authorized] COVID-19 vaccines are safe,” Dr. Aleena Banerji, clinical director of the Allergy and Clinical Immunology Unit at MGH and associate professor at Harvard Medical School, said in a news release.
The Centers for Disease Control and Prevention also recommends people with a history of severe allergic reactions “not related to vaccine or injectable medications, such as food, pet, venom, environmental or latex allergies get vaccinated.” Those with a history of allergies to oral medicines or a family history of severe allergic reactions are also in the clear.
But the agency cautions against vaccination for individuals who have had any kind of immediate allergic reaction — when treatment with an epinephrine pen or a hospital visit is necessary — to any ingredient in the Pfizer-BioNtech or Moderna vaccine.
These “immediate” reactions can include hives, swelling and wheezing.
The same advice goes for people who have had a severe allergic reaction to their first dose of either vaccine. The CDC says this group should not get the second dose, which is required for full protection, experts say.
What ingredients are in the COVID-19 vaccines?
Both the Pfizer-BioNTech and Moderna vaccines contain one active ingredient: mRNA.
The vaccines release this molecule — a subtype of RNA that makes up the coronavirus’s genetic material and can already be found in our bodies — into our cells. This mRNA carries directions that teach our cells to produce antibodies against the coronavirus.
The rest are inactive ingredients called excipients.
Excipients “are necessary and added to a vaccine for specific purposes such as stimulating a stronger immune response, preventing contamination by bacteria or stabilizing the potency of the vaccine during transportation and storage,” the team of allergists said in their article.
Some of the inactive ingredients include a variety of lipids, or fats that form a shell around the mRNA molecules and “help keep [it] intact and stable until it gets into your body and starts doing its work,” Dr. William Schaffner, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, told Health in December.
The rest of the ingredients are salts, such as potassium chloride and sodium acetate, sugars (sucrose) and other buffers that help maintain stability.
“There is nothing on this ingredients list that is shocking,” Dr. Schaffner told Health.
The team of allergists also said panic attacks and other anxiety reactions that include shortness of breath, lightheadedness and rapid heart beat during the vaccination process can make it seem as though someone is experiencing an allergic reaction.
Experts say side effects such as arm soreness, fevers, headaches, fatigue and muscle aches after vaccination are normal and should be expected. They are signs that your immune system is creating the response it needs to fight the coronavirus if infected.
This story was originally published January 4, 2021 at 3:41 PM with the headline "What’s in the COVID vaccine? Doctors assure allergy-sufferers it’s OK to get the shot."
