COVID-19 vaccine guide for youth and adults (12 years and over): Contraindications, precautions and allergic reactions

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Table 2. Management options for contraindications and precautions
Contraindication or precaution Management options

Severe allergic reaction (for example, anaphylaxis) after previous administration of a COVID-19 vaccine

Consultation with an allergist or other appropriate physician should be sought.

  • If benefits outweigh the potential risks and informed consent is provided, the same COVID-19 vaccine or a vaccine using the same platform that resulted in the allergic reaction may be offered.
  • If re-vaccinated, vaccine administration should be done in a controlled setting with expertise in managing anaphylaxis. The patient should be observed for at least 30 minutes after revaccination.

Severe allergy to any component of the specific COVID-19 vaccine

(Refer to Table 3 entitled "Ingredients of available COVID-19 vaccines that have been associated with allergic reactions and some other products where they may be found" for more information on allergens)

  • For people allergic to polyethylene glycol (PEG), a consultation with an allergist is recommended
  • For people allergic to tromethamine, use the Pfizer-BioNTech Comirnaty vaccine (adult/youth formulation)
  • For people allergic to polysorbate, use an mRNA vaccine

Patients who have experienced venous or arterial thrombosis with thrombocytopenia following vaccination (VITT) with a viral vector COVID-19 vaccine

  • Should not receive a second dose of a viral vector COVID-19 vaccine
  • Can receive an mRNA vaccine for the second dose in consultation with a thrombosis expert

People who experienced inflammation of the heart or lining of the heart (myocarditis or pericarditis) after a previous dose of an mRNA vaccine

  • Should not receive another dose of COVID-19 vaccine at this time
  • More information will become available to guide advice in this area

People who experienced a previous episode or were previously diagnosed with capillary leak syndrome

  • Should not receive AstraZeneca Vaxzevria or Janssen COVID-19 vaccine
  • An mRNA vaccine may be offered

People with a history of thrombocytopenia (low platelets)

  • mRNA vaccines are preferred by NACI
  • Immune thrombocytopenia is now listed as a very rare adverse event following viral vector vaccines
  • If using a viral vector vaccines and there is a history of thrombocytopenia, platelets should be monitored post-vaccination

People with risk factors for thromboembolic events

  • mRNA vaccines are preferred by NACI
  • Venous thromboembolism is now listed as a very rare adverse event following viral vector vaccines
Precautions Management options

12 to 29 years of age

  • To minimize the risk of myocarditis/pericarditis, NACI has indicated that Pfizer-BioNTech Comirnaty is the preferred vaccine for the primary series in those 12 to 29 years of age and may be the preferred product for the booster dose in those 18 to 29 years of age.
  • NACI notes that moderately and severely immunocompromised individuals may benefit from the slightly higher antibody levels generated and slightly higher vaccine effectiveness provided by the Moderna 100 mcg vaccine compared to the Pfizer-BioNTech 30mcg vaccine. Moderna Spikevax may be considered for those who are moderately or severely immunocompromised based on clinical judgment.

Mild to moderate immediate allergic reactions after a previous dose of authorized COVID-19 vaccines or any of its components

(Refer to Table 3 entitled "Ingredients of available COVID-19 vaccines that have been associated with allergic reactions and some other products where they may be found" for more information on allergens)

  • Vaccination with the same platform may be considered if:
    • benefits outweigh the potential risks
    • informed consent is provided
  • Assessment by a physician or nurse with expertise in immunization may be warranted
  • If revaccinated, should be observed for at least 30 minutes after vaccination

Proven severe allergic reaction (for example, anaphylaxis) to injectable therapy not related to a component of authorized COVID-19 vaccines (for example, related to other intramuscular or subcutaneous vaccines, or injectable or intravenous therapies)

  • May be routinely vaccinated without the need for a specific assessment
  • Should be observed for at least 30 minutes after vaccination

Suspected but unproven allergy to a vaccine component

(Refer to Table 3 entitled "Ingredients of available COVID-19 vaccines that have been associated with allergic reactions and some other products where they may be found" for more information on allergens)

  • May be routinely vaccinated without the need for a specific assessment
  • Should be observed for at least 30 minutes after vaccination

History of allergy not related to a component of authorized COVID-19 vaccines or other injectable therapy (for example, related to foods, oral drugs, insect venom or environmental allergens)

  • Can receive COVID-19 vaccines without any special precautions
  • Should be observed for 15 minutes after vaccination

Previous history of myocarditis or pericarditis unrelated to mRNA vaccines

  • Should consult their clinical team for individual considerations and recommendations
  • If they are no longer being followed clinically for cardiac issues, they should receive an mRNA vaccine
Table 3. Ingredients of available COVID-19 vaccines that have been associated with allergic reactions and some other products where they may be found
Vaccine product Potential allergen included in the vaccine Other products where the potential allergen may be foundTable 3 Footnote *
Pfizer-BioNTech Comirnaty COVID-19 vaccine (adult/youth formulation) Polyethylene glycol (PEG)Table 3 Footnote aTable 3 Footnote bTable 3 Footnote c Over the counter (for example, cough syrup, laxatives) and prescription medications, medical bowel preparation products for colonoscopy, skin care products, dermal fillers, cosmetics, contact lens care solutions, products such as ultrasound gelTable 3 Footnote d
Moderna Spikevax COVID-19 vaccine Polyethylene glycol PEGTable 3 Footnote aTable 3 Footnote bTable 3 Footnote c Over the counter (for example, cough syrup, laxatives) and prescription medications, medical bowel preparation products for colonoscopy, skin care products, dermal fillers, cosmetics, contact lens care solutions, products such as ultrasound gelTable 3 Footnote d
TromethamineTable 3 Footnote e
(trometamol or Tris)
Contrast media, oral and parenteral medications
AstraZeneca Vaxzevria COVID-19 vaccine and Janssen COVID-19 vaccine Polysorbate 80Table 3 Footnote c Medical preparations (for example, vitamin oils, tablets, and anticancer agents), cosmeticsTable 3 Footnote f
Table 3 Footnote *

This is not a complete list of products.

Table 3 Return to footnote * referrer

Table 3 Footnote a

Medications that contain PEG are described in Stone and others. DOI:10.1016/j.jaip.2018.12.003

Table 3 Return to footnote a referrer

Table 3 Footnote b

A review of immediate type hypersensitivity reactions to PEG is available in Wenande and others. DOI: 10.1111/cea.12760

Table 3 Return to footnote b referrer

Table 3 Footnote c

There's a potential of cross-reactive hypersensitivity between PEG and polysorbates

Table 3 Return to footnote c referrer

Table 3 Footnote d

PEG is an additive in some food and drinks but allergic reactions to PEG in food or drinks have not been documented

Table 3 Return to footnote d referrer

Table 3 Table 3 Footnote e

One case report of anaphylaxis to tromethamine has been described in Lukawska and others. DOI: 10.1016/j.jaip.2018.08.035

Table 3 Return to footnote e referrer

Table 3 Footnote f

Case reports of anaphylaxis to polysorbate 80 have been described in Badiu and others (DOI: 10.1136/bcr.02.2012.5797) and Palacios Castaño and others (DOI: 10.18176/jiaci.0109)

Table 3 Return to footnote f referrer

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