What are the safety considerations for administering COVID-19 (Coronavirus Disease 2019) and flu (influenza) vaccines to individuals undergoing allergy immunotherapy?

Safety of COVID-19 and Flu Vaccines Following Allergy Immunotherapy

COVID-19 and influenza vaccines can be safely administered to individuals undergoing allergy immunotherapy, with standard monitoring precautions recommended for all vaccine recipients. 1, 2

General Safety Considerations

• COVID-19 vaccines and influenza vaccines can be administered simultaneously or sequentially without compromising safety or efficacy 1
• Both vaccines can be administered to individuals with a history of allergies, including those undergoing allergy immunotherapy, as long as they don't have specific contraindications to vaccine components 1
• Patients with allergic diseases should be monitored for at least 15-30 minutes after vaccination, with a longer observation period (at least 2 hours) recommended for patients with systemic lupus erythematosus or history of severe allergic reactions 1

Specific Considerations for COVID-19 Vaccines

• The primary allergic concern with COVID-19 vaccines relates to excipients rather than the active components - polyethylene glycol (PEG) in mRNA vaccines and polysorbate 80 in adenoviral vector vaccines 1, 3
• Anaphylaxis after COVID-19 vaccination is rare, with an estimated rate of 11.1 cases per million doses for the Pfizer-BioNTech vaccine 4
• Patients with a history of allergic reactions to vaccine ingredients, including PEG or polysorbate, should not receive vaccines containing those components 1
• Recent research shows that individuals with a history of allergy reported more adverse reactions to COVID-19 vaccines than the general population, but most were not serious and no cases of anaphylaxis were reported in a large European surveillance study 5

Specific Considerations for Influenza Vaccines

• Influenza vaccines can be safely administered to individuals with allergies, including those on allergy immunotherapy 1
• Egg allergy is not a contraindication or precaution for receiving influenza vaccines 1
• For patients with a history of severe allergic reaction to a previous influenza vaccine, evaluation by an allergist is recommended before receiving future influenza vaccines 1

Timing Considerations

• There is no need to adjust the timing of allergy immunotherapy in relation to COVID-19 or influenza vaccination 2
• COVID-19 vaccines and influenza vaccines can be administered simultaneously or at any interval without safety concerns 1, 2
• When administering multiple vaccines simultaneously, they should be given at separate anatomic sites to minimize local reactions 1, 2
• If vaccines with increased reactogenicity (such as high-dose influenza vaccine) are administered with COVID-19 vaccines, they should be given in different limbs 1

Contraindications and Precautions

• The only absolute contraindication to receiving either vaccine is a history of severe allergic reaction (anaphylaxis) to a previous dose of the same vaccine or to any component of the vaccine 1
• Moderate to severe acute illness, including COVID-19, is a precaution for vaccination, and administration should be deferred until symptoms resolve 1
• A history of Guillain-Barré syndrome within 6 weeks of a previous influenza vaccination is a precaution for influenza vaccination 1

Clinical Approach

• Take a detailed history of previous allergic reactions, particularly to vaccines or injectable medications 1
• For patients with a history of anaphylaxis to any substance, monitor for at least 30 minutes after vaccination 1
• Ensure appropriate emergency medications and equipment are available at the vaccination site 4
• For patients with a history of allergic reactions to vaccine components, consider skin testing for PEG and polysorbate before vaccination 1

Special Situations

• For patients with a history of allergic reactions after the first dose of a COVID-19 vaccine, consultation with an allergist can help determine if subsequent doses can be safely administered 6
• Studies have shown that patients who received allergist advice and evaluation before COVID-19 vaccination were able to safely complete their vaccination series, even those with a history of allergic reactions 6