Egg allergy and yellow fever vaccination

Area of Science:

• Immunology
• Vaccinology
• Allergology

Background:

• Individuals with hen's egg allergy often face concerns regarding Yellow Fever Vaccine (YFV) administration due to vaccine production methods.
• Identifying reliable biomarkers is crucial for safely managing YFV vaccination in this population.
• Understanding risk factors for adverse events after immunization (AEAI) is essential for patient safety.

Purpose of the Study:

• To evaluate biomarkers for safely guiding Yellow Fever Vaccine (YFV) vaccination in individuals with suspected hen's egg allergy.
• To identify factors associated with an increased risk of adverse events after immunization (AEAI).

Main Methods:

• Patients underwent skin prick tests (SPT) and intradermal tests (IDT) with egg allergens and YFV.
• Serum specific IgE (sIgE) levels for various egg proteins were measured.
• YFV desensitization was performed for sensitized patients; others received YFV and were monitored.

Main Results:

• 103 patients were enrolled; 71% experienced reactions to YFV.
• Positive YFV skin test results were significantly associated with reaction severity (OR: 7.64).
• Specific IgE to ovomucoid was the only biomarker linked to clinical symptoms (p=0.025).

Conclusions:

• A correlation exists between positive egg component tests and clinical reaction severity.
• Ovomucoid and conalbumin may be potential indicators, but further research is needed.
• Current recommendations support using YFV testing when necessary for vaccination guidance.