What are the alternatives to traditional flu vaccines for individuals with egg allergies?

Alternatives to Traditional Flu Vaccines for Individuals with Egg Allergies

For individuals with egg allergies, recombinant influenza vaccine (RIV) is the preferred option as it is completely egg-free, while cell culture-based inactivated influenza vaccine (ccIIV) is another suitable alternative with minimal theoretical egg protein content. 1

Available Egg-Free and Low-Egg Options

• Recombinant Hemagglutinin Vaccine (RIV):

  • Completely egg-free (FluBlok Quadrivalent) 1
  • Indicated for persons aged 18 through 49 years (original FluBlok) or ≥18 years (newer quadrivalent formulation) 1
  • Manufactured without the use of influenza viruses or eggs 2
  • Safe for persons with egg allergy of any severity 1

• Cell Culture-Based Inactivated Influenza Vaccine (ccIIV):

  • Flucelvax Quadrivalent - viruses propagated in mammalian cells rather than eggs 1
  • Contains extremely minimal theoretical egg protein (maximum of 1.7×10-8 μg/0.5 mL dose) 1
  • Indicated for persons aged ≥18 years (original trivalent version) or ≥4 years (quadrivalent version) 1, 3
  • Manufactured using a process that significantly dilutes any potential egg protein 1

Recommendations Based on Severity of Egg Allergy

For Patients with History of Only Hives After Egg Exposure:

• Any age-appropriate influenza vaccine can be administered without special precautions 1, 2
• No special observation period beyond the standard 15 minutes is required 1, 2
• No need for administration in a specialized medical setting 1

For Patients with More Severe Egg Allergy Reactions:

• Symptoms such as angioedema, respiratory distress, lightheadedness, or recurrent emesis 1
• Any age-appropriate influenza vaccine can still be used, including egg-based vaccines 1
• Administration should occur in an inpatient or outpatient medical setting with supervision by healthcare providers able to recognize and manage severe allergic reactions 1
• RIV is preferred if age-appropriate as it contains no egg protein 1, 2

Important Clinical Considerations

• Egg allergy testing is not required before influenza vaccination 2
• A previous severe allergic reaction to influenza vaccine itself (regardless of the component suspected) is a contraindication to future receipt of the vaccine 1
• For persons with no known history of egg exposure but with positive allergy testing results, consultation with an allergist is recommended before vaccination 1
• All vaccine providers should be familiar with their office emergency plan and be certified in cardiopulmonary resuscitation 1

Advantages of Non-Egg-Based Vaccines

• Avoid potential concerns about egg adaptation affecting vaccine effectiveness 3, 4
• Circumvent manufacturing limitations associated with egg-based production 5, 4
• Provide alternatives for the growing population with egg allergies 2
• May potentially offer improved effectiveness compared to egg-based vaccines in some seasons 3

Common Pitfalls to Avoid

• Unnecessarily delaying vaccination due to egg allergy concerns 2
• Assuming all patients with egg allergy need specialized administration protocols 1, 2
• Referring patients with only hives after egg exposure for specialized vaccination when standard administration is appropriate 1
• Failing to recognize that even patients with severe egg allergies can receive any age-appropriate influenza vaccine with proper precautions 1