COVID-19 Vaccine FAQ Series - Questions about allergies, advice, and special circumstances

Midwest Allergy Sinus Asthma, SC

COVID-19 Vaccine FAQ Series
By Tamara Reeter, NP and Dareen Siri, MD
*created 1/7/21 and subject to change.

Many of our patients are asking us about details regarding COVID-19 and the COVID-19 vaccines. Given MASA, the Food Allergy Center, and SWIA’s expertise in allergy, immunology, medicine and clinical research, we have collected and digested information from validated sources as we begin a Q&A series which will address the majority of questions that our patients have. These documents are intended for general information and should not be taken as specific advice to your particular situation since good care for all patients should be individualized.

Announcement to Patients about COVID-19 (March 2020)
Q&A 1. Background on COVID-19
Q&A 2. What you need to know about the COVID-19 Vaccine.
Q&A 3. Questions about efficacy and safety.
Q&A 4. Questions about allergies, advice, and special circumstances.

Allergies, anaphylaxis, special circumstances, and general advice is reviewed in this section.

1. Can you tell me about the allergic reactions that have been reported thus far?

As many of our allergy and immunology patients are aware, allergic reactions may occur to proteins and other substances, including vaccines. Anaphylaxis is a life-threatening allergic reaction that does occur rarely after vaccination, with onset typically within minutes to hours.

Based on reports of allergic reactions to the COVID-19 vaccines, the CDC has published a guidance document, “Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Pfizer-BioNTech COVID-19 Vaccine — United States, December 14–23, 2020.”

During December 14–23, 2020, monitoring by the Vaccine Adverse Event Reporting System detected 21 cases of anaphylaxis after administration of a reported 1,893,360 first doses of the Pfizer-BioNTech COVID-19 vaccine (11.1 cases per million doses); 71% of these occurred within 15 minutes of vaccination.

Below is a summary of the report:

175 cases were reported and reviewed.

21 cases of anaphylaxis. (11.1 per Million doses administered)* 86 cases of allergic reactions but not full anaphylaxis.**
61 cases of non-allergic adverse events.
7 cases still under investigation.

*Of 21 confirmed anaphylaxis cases:

17 (81%) had documented history of allergies or allergic reactions

-including to drugs or medical products, foods, and insect stings

7 (33%) had a history of previous anaphylaxis

-1 after rabies vaccine, 1 after influenza A(H1N1) vaccine

Median age = 40 years (range = 27–60 years)
Gender = 19 (90%) cases occurred in females
No geographic clustering was noted.
No vaccine lots were identified as causative.

Reaction time(Median time was 13 mins, Range 2-150 mins):
<15 mins = 15 (71%) patients
15 to 30 mins = 3 (14%) patients
>30 mins = 3 (14%)

19 of 21 (90%) patients were treated with epinephrine.

1 Subcutaneous epi
18 Intramuscular epi (this is the standard of care)

4 (19%) were hospitalized (3 in the ICU)
17 (81%) were treated in ED
20 (95%) were recovered or discharged home at the time of the report
No deaths from anaphylaxis were reported.

**Of 86 allergic, non-anaphylaxis cases:

83 with symptom onset 0-1 day risk window.

72 (87%) of which were classified as nonserious
56 (67%) cases reported a past history of allergies or allergic reactions

Commonly reported symptoms:

Itchy and scratchy throat Mild respiratory symptoms.

Median age = 43 years (range = 18–65 years)
Gender = 75 (90%) occurred in women

Reaction time(Median time was 12 minutes, Range <1 min–20 hours):

Within 30 mins = 61 (85%) cases
>30 mins = in 11 cases
No data = 11 cases

2. What is suspected to cause hypersensitivity reactions to the COVID-19 vaccines?

Both the Pfizer and Moderna vaccines contain Polyethylene Glycol (PEG), as a type of stabilizer. PEG is an ingredient in many common foods, medications, and products, including Miralax and bowel prep oral solutions (prior to colonoscopy). PEG is suspected to be the culprit to some of the allergic and allergic-like reactions that have been evidenced so far. Other products that contain PEG have also rarely caused anaphylaxis. As noted, anaphylaxis and allergic reactions to PEG is uncommon; however precautions at this time should be exercised since PEG has not been previously used in an approved vaccine until now.

3. Who should exercise caution and seek further guidance with the vaccine? What is recommended for those with allergies and anaphylaxis?

Vaccines do not contain food products such as egg, milk, gelatin or peanut. Neither do they contain preservatives or latex. Having mild or moderate allergic rhinitis, asthma, eczema, or food allergy, at this time, are NOT contraindications to receiving COVID-19 vaccines. Having a

severe allergic reaction history is also NOT a contraindication but good judgement should be taken in such cases.

Again, caution should be exercised upon the receipt of the COVID-19 vaccine as noted below in the general recommendations. The information is largely based on reports of reactions from the Pfizer vaccine. Reports of anaphylaxis have also occurred with the Moderna vaccine but so far has been less frequent. Given our collective experience with unusual allergies, management of allergic cases, and history of treating many cases of anaphylaxis, we have formulated some guidelines and precautions below. For specific questions, please schedule a telephone consultation to discuss your specific situation so that we may review your allergy and reaction history and your special circumstances.

A higher risk of allergic reaction may occur in:

  • ●  Females
  • ●  Previous history of severe allergic reactions and/or anaphylaxis (to any product)
  • ●  Previous history of reactions to medications or vaccines
  • ●  Previous history of reaction to polysorbate
  • ●  Mast Cell Disorder, including Mast Cell Activation Syndrome
  • ●  History of idiopathic anaphylaxis
  • ●  Those who have an increased risk of allergic reactions should also consider additional precautions if you are taking an ACE-Inhibitor (Angiotensin converting enzyme inhibitor) or beta-blocker medications. These medicines are commonly used to treat high blood pressure or heart conditions and may predispose to more severe allergic reactions should they occur. Consider:
  • ●  Prior to your vaccine appointment, avoid doing anything that is not a part of your ordinary routine (such as taking a new medicine or travel). These techniques are also to ensure that you are healthy and well prior to getting vaccinated.
  • ●  Take a non-sedating antihistamine at least 1 hour before the vaccine.
  • ●  Rest and be observed at the healthcare facility for at least 30 minutes.
  • ●  If you have an epinephrine auto-injector, carry it with you to your vaccination appointment and keep it with you for the day.
  • ●  Have a responsible friend or family member drive you to your appointment.
  • ●  Avoid exercise, alcohol, stress, and activities that increase body temperature for several hours after the vaccination. Get plenty of rest and sleep in the next few days.
  • ●  Continue good hygiene and social-distance measures to avoid getting ill.
  • ●  Avoid new activities, medications, and products for a couple of days after the vaccination. Taking medications that you have taken and tolerated before, such as acetaminophen or ibuprofen, to counteract discomfort from the vaccination is okay.
  • ●  Activate your anaphylaxis emergency plan if you have one, and report to the emergency department or call 911 if you experience a severe allergic reaction.

*There does not exist any literature to support these recommendations but are common sense techniques to decrease allergic reactions. Our expertise in allergy-immunology and managing

allergic reactions from shots, vaccines, foods, etc. imparts to us the knowledge that pre-medicating with an antihistamine and avoidance of exercise, alcohol, and stress, often lead to improved tolerability and less reactions.

4. Are there other special circumstances that should be considered?

Discuss risks and benefits of getting a COVID-19 vaccination with your doctor if you have or have a history of:

  • Bell’s Palsy
  • Guillain-Barre syndrome
  • Encephalopathic diseases
  • Active moderate to severe respiratory infection (non-COVID-19)

5. What if I have an immunodeficiency or am taking an immunosuppressant medicine?


It is important to note that those with severe immunodeficiencies, including those who are taking immunosuppressant medications such as high dose steroids and chemotherapy, are medically prioritized to receive the COVID-19 vaccination, since such persons are considered to have medical comorbidities (this means a higher risk of a poor outcome should you be infected). However, due to problems with the immune system, such people may not mount an adequate immune response after the vaccination and may still be susceptible to getting COVID-19. Our advice is that any protection is better than no protection. (As of 2024, there are options available for Covid-19 prevention for immunodeficient individuals. Please contact our office to discuss with medical providers about your options.)

6. Who should not receive the vaccine?

  • ●  Those with an active COVID-19 infection
  • ●  Those who have an allergy to PEG (and polysorbate)
  • ●  Previous reaction to the COVID-19 vaccine

Those who have a severe allergic reaction or anaphylaxis to their FIRST COVID-19 vaccine are NOT advised to get a second shot.

Those who have allergic reactions that are not considered anaphylaxis should strongly consider a consultation with us prior to the 2nd vaccine administration.

Administration of the COVID-19 vaccines are likely to occur in a facility with trained personnel or may treat allergic reactions should they occur. The CDC recommends emergency equipment be available, as well as medicines to treat allergic reactions. Those patients who have concerns about allergic reactions should carefully consider which facility they will choose to receive their vaccination, if given a choice in the future. Those with the history of anaphylaxis should be monitored onsite for 30 minutes and all others for 15 minutes.

7. What happens if I cannot get the 2nd shot due to an allergic reaction?

All current studies in the development of the COVID-19 vaccines evaluated short-term data and were designed to study a 2-vaccination scheme. Although it is unclear how effective a single-vaccine is, it is clear from the studies so far that protection is afforded early on from the first shot and still reduces the risk of COVID-19. As discussed above, additional studies are needed to evaluate the long-term efficacy, as well as the efficacy of a single vaccination with the COVID-19 vaccine.

N Petrosillo et al.COVID-19, SARS and MERS: are they closely related? Clin Microbiol Infect 2020 Jun;26(6):729-734. ing-schedules-covid-19-vaccines