The Pfizer-BioNTech, Moderna, and now Janssen (Johnson & Johnson) COVID-19 vaccines have been approved for use in the United States.

As allergists, we know there is a rare risk of anaphylaxis to vaccines.  According to an update from CDC, the reported rate of anaphylaxis is 4.7 cases/million doses following administration of the Pfizer BioNTech vaccine and 2.5 cases/million following administration of the Moderna vaccine.  These rates will likely decline as more doses are administered and will likely not be significantly different from one another.

The CDC has issued clear safety recommendations regarding receiving the vaccine for those with a history of allergic reactions. The Center presented this algorithm to assist with decision-making regarding who can safely receive the COVID-19 vaccine. Individuals with common allergies to medications, foods, inhalants, insects, and latex are no more likely than the general public to have an allergic reaction to the COVID-19 vaccine.  Those with a history of a severe allergic reaction (e.g. anaphylaxis) due to any cause should be monitored for a 30-minute observation period if vaccinated with the COVID-19 vaccine.

What Ingredients are in the COVID-19 Vaccines?

The Pfizer-BioNTech, Moderna, and Janssen COVID-19 vaccines do not contain eggs, preservatives, or latex.

  • Pfizer-BioNTech Vaccine:

Ingredients in vaccine for 6 month-11 year old

Ingredients in vaccine for 12 year old +

  • Moderna Vaccine:


  • Johnson & Johnson Vaccine: 

Polyethylene glycol (PEG) is an ingredient in both mRNA COVID-19 vaccines, and polysorbate 80 is an ingredient in Janssen COVID-19 vaccine. PEG and polysorbate are structurally related, and cross-reactive hypersensitivity between these compounds may occur. People with a contraindication to one of the mRNA COVID-19 vaccines should not receive doses of either of the mRNA vaccines (Pfizer-BioNTech or Moderna). However, people with a contraindication to mRNA COVID-19 vaccines may be able to receive Janssen COVID-19 vaccine, and vice versa, provided certain measures are taken. As a change from previous versions of the guidance, known polysorbate allergy is no longer a contraindication to mRNA vaccination; however, known polysorbate allergy is a contraindication to Janssen COVID-19 vaccine and thus, a precaution to mRNA COVID-19 vaccination.

  • People with a contraindication to mRNA COVID-19 vaccines (including due to a known PEG allergy): Consideration may be given to vaccination with Janssen COVID-19 vaccine. People who have received one mRNA COVID-19 vaccine dose but for whom the second dose is contraindicated should wait at least 28 days after the mRNA vaccine dose to receive Janssen COVID-19 vaccine.
  • People with a contraindication to Janssen COVID-19 vaccine (including due to a known polysorbate allergy): Consideration may be given to mRNA COVID-19 vaccination.

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Please set up a visit with your allergist for further discussion and concerns.