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Vaccine: Allergy and Ingredient-Related FAQs

1. Do people with a sulfa allergy have any increased risk of allergic reactions to the COVID vaccine?
There are no components of the COVID vaccine that present any specific risk with sulfa allergies.  In general, patients with severe allergic reactions to any drug are requested to stay for 30 minutes, rather than 15 minutes, as an added precaution.

2. What if I have a latex allergy? An egg allergy?
There is no latex in this product or its packaging.  Latex allergy is not a contraindication.

Neither Moderna or Pfizer vaccine contains eggs. The mRNA vaccine does not require the use of eggs or any other cells in the production or manufacturing process.  Therefore, egg allergy is not a concern with this vaccine.

3. Does the COVID vaccine contain fetal cells?
Neither the Moderna or Pfizer vaccine contains fetal cells.  The mRNA vaccine process is entirely cell free.  No living organisms or cells are needed in the manufacturing process.

The Johnson & Johnson vaccine uses a virus called an “adenovirus” that has been stripped of its ability to cause infection, in order to assist the immune system.  The virus lacks the ability to replicate, or reproduce. This adenovirus is grown in PER.C6 TetR cells.  This cell line was isolated from a fetus that was terminated in 1985.  While a fetal cell line as used in the manufacturing/production of the adenovirus component of the vaccine, there are no fetal cells in the vaccine itself.

4. If I have been diagnosed with drug allergies (antibiotics/penicillin) and am advised not to take other preventative vaccines like flu, pneumonia, etc. will the COVID vaccine cause the same risk?
There are no antibiotic-related components involved in the manufacturing of, or final ingredients of the COVID vaccine. Some vaccines have utilized small amounts of certain classes of antibiotics. Before foregoing important preventative vaccines due to allergy history, it is strongly advised to consult with an allergist to assess which vaccines should or should not be avoided (if any).

5. I had a significant allergic reaction to a previous vaccine or other injectable medication. Can I still get the COVID vaccine?
The CDC considers this a precaution.  While you may still get the COVID vaccine, it may be advisable to consult an Allergist prior to receiving either COVID vaccine.

Those who have a history of allergic reactions to any vaccine will be asked to wait longer after their injection, and will be monitored carefully. The significant majority of allergic reactions would happen shortly after the vaccine is administered.

6. What is an mRNA vaccine?

mRNA stands for messenger ribonucleic acid.  mRNA is a genetic sequence that provides the blueprint for something to be developed in a cell (generally a protein). The two mRNA vaccines currently being used are the Pfizer and Moderna vaccines.

The COVID-19 mRNA vaccine contains a small piece of genetic material created in a lab.  This mRNA creates a blueprint for a small part of the SARS-2-Coronavirus called the “spike protein.”  This is the part of virus that causes the immune system to recognize that it needs to make antibodies toward this virus.

The mRNA vaccine CANNOT cause an actual infection, as the only part of the template is for the spike protein, and not for the actual virus itself.  mRNA also cannot change a person’s DNA, as mRNA would have to get in the nucleus of the cell to do so.  (If scientists/doctors could change DNA, there would be cures for all inherited diseases and cancer.)

7. I had a reaction to the first mRNA vaccine, should I get the second vaccine?
It depends on what the reaction to the first vaccine was.  The CDC recommends the following contraindications to vaccination with both the Pfizer and Moderna vaccines
  • Severe allergic reaction (ie anaphylaxis) after a previous dose of an mRNA COVID-19 vaccine or any of its components
  • Immediate allergic reaction of any severity to a previous dose of an mRNA COVID-19 vaccine or any of its components
  • Immediate allergic reaction of any severity to polysorbate (due to potential cross-reactive hypersensitivity with the vaccine ingredient PEG)
CDC recommends these individuals should not receive either mRNA COVID vaccine unless they have been evaluated by an allergist-immunologist and it is determined that they can safely receive the vaccine.

Non-allergic reactions such as light-headedness, feeling dizzy, or fainting (also known as vasovagal reactions) or post-vaccination side effects such as muscle aches, fever, and fatigue, are not contraindications to receiving the second dose.

8. Does the vaccine contain any pork or gelatin products?

Neither the Pfizer or Moderna vaccine contain pork or gelatin products and are considered “halal” (aka lawful) by the Muslim community.  The lipid component in the Pfizer vaccine is derived from plant sources or are synthetic.  The vaccine contains no animal components.

The Johnson & Johnson vaccine is free of any animal-derived proteins as well.

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