Can a 55-year-old patient with a history of hives after consuming egg-containing products safely receive an influenza vaccine, such as Inactivated Influenza Vaccine (IIV), Recombinant Influenza Vaccine (RIV4), Live Attenuated Influenza Vaccine (LAIV4), or cell culture-based Inactivated Influenza Vaccine (ccIIV4)?

Influenza Vaccination in a 55-Year-Old with Hives After Egg Exposure

Yes, this patient can safely receive any age-appropriate influenza vaccine (IIV, RIV4, LAIV4, or ccIIV4) without any special precautions beyond standard vaccination protocols. 1

Direct Recommendation

For patients with a history of only hives (urticaria) after egg exposure, any licensed, recommended influenza vaccine that is otherwise appropriate for age and health status may be administered. 1 This represents a significant evolution from older guidelines that required special safety measures. 1

The 2019 CDC/ACIP guidelines explicitly state that persons with egg allergy who have experienced only urticaria after egg exposure should receive influenza vaccine, and any licensed, recommended vaccine (IIV, RIV4, or LAIV4) appropriate for their age may be used. 1

Available Vaccine Options for This Patient

All of the following are appropriate choices for a 55-year-old with hives-only egg allergy:

• Inactivated Influenza Vaccine (IIV): Standard egg-based vaccine containing trace amounts of egg protein (≤1 μg/0.5mL dose), can be administered without special precautions 1, 2

• Recombinant Influenza Vaccine (RIV4): Completely egg-free, manufactured without eggs, approved for ages ≥18 years 3, 4

• Cell Culture-Based IIV (ccIIV4): Contains theoretical maximum of 1.7×10⁻⁸ μg/0.5 mL dose of egg protein, approved for ages ≥4 years 3

• Live Attenuated Influenza Vaccine (LAIV4): Appropriate if aged 18-49 years and no other contraindications exist 1

Administration Protocol

No special safety measures are required beyond standard vaccination protocols:

• No skin testing is necessary 1, 4, 2
• No divided-dose administration is required 1, 4
• No extended observation period beyond the standard 15-minute post-vaccination monitoring (recommended for all vaccines to assess for syncope) 1, 4
• No requirement for administration by a provider with specific egg allergy expertise 1

Standard Safety Requirements (Apply to All Vaccine Recipients)

The vaccination setting must have:

• Personnel and equipment for rapid recognition and treatment of anaphylaxis 1, 2
• Providers familiar with the office emergency plan and certified in cardiopulmonary resuscitation 1, 2
• Standard 15-minute observation period to decrease risk of injury from syncope 1, 4

Critical Distinction: Severe Egg Allergy vs. Hives-Only

This patient does NOT fall into the severe allergy category. The guidelines distinguish between:

Hives-only reactions (this patient): Any vaccine, no special precautions 1, 4

Severe reactions (angioedema, respiratory distress, lightheadedness, recurrent vomiting, or requiring epinephrine): Any age-appropriate vaccine can still be used, but must be administered in a medical setting with supervision by a provider capable of managing severe allergic reactions 1, 4

Evolution of Guidelines and Supporting Evidence

The recommendations have liberalized significantly over time. The 2013 guidelines required 30-minute observation periods and administration by providers familiar with egg allergy manifestations for patients with hives-only reactions. 1 However, the 2019 and current 2024 guidelines eliminated these requirements based on extensive safety data showing no cases of anaphylaxis in egg-allergic persons receiving egg-based influenza vaccines. 2

Multiple studies have demonstrated that egg-allergic recipients are no more likely than those without egg allergy to suffer anaphylactic reactions to influenza vaccine. 5 Reviews of studies administering egg-based influenza vaccines to persons with egg allergy noted no cases of anaphylaxis or serious hypersensitivity reactions. 2

Common Pitfalls to Avoid

• Do not unnecessarily delay vaccination due to egg allergy concerns when only hives have occurred 4
• Do not perform skin testing for hives-only egg allergy, as this is no longer recommended 4, 2
• Do not use divided-dose protocols, as these are no longer recommended for patients with egg allergy 4
• Do not restrict to egg-free vaccines only, as any age-appropriate vaccine is acceptable 4
• Do not confuse egg allergy with previous severe allergic reaction to influenza vaccine itself, which remains a contraindication to future influenza vaccination 1, 2

Clinical Verification

If there is uncertainty about the severity of the egg allergy, consider that persons who can eat lightly cooked egg (e.g., scrambled egg) without reaction are unlikely to be truly allergic. 1, 4 However, tolerance to egg-containing baked products does not exclude the possibility of egg allergy. 1