Vaccine allergy evaluation and management at the specialized Green Channel Consultation Clinic.

Background: Suspected vaccine allergy may be a cause of incomplete or delayed vaccination. Patients at risk of adverse reactions or suspected contraindications need specialized consultation about subsequent vaccinations.

Objective: To analyse consultancy results for patients at risk of allergic reactions to vaccines as evaluated by the Green Channel University Hospital Immunization Consultancy Clinic.

Methods: A review of cases of allergic reactions to vaccines or contraindications due to underlying diseases or sensitization to vaccine components submitted to the Green Channel was carried out. Analysed data included detailed clinical reaction history, skin and in vitro allergy testing with vaccine components, recommendations for vaccination and outcome of subsequent vaccine administrations.

Results: A total of 519 cases, 370 referred for previous local or systemic reactions to vaccines, mostly cutaneous, and 149 sent for suspected contraindications were evaluated. Skin testing was performed on 152 patients, specific IgE determination in 37 subjects and patch testing in 173 cases. After consultation, 442 (85%) subjects were advised to continue vaccination, with personalized precautions (premedication, or alternative brand, or administration in graded doses) for 200 of them. Among the 352 (80%) patients vaccinated as per Green Channel instructions, 33 subjects (9.3%) reported mild allergic or non-specific symptoms and one (0.3%) urticaria with bronchospasm.

Conclusion And Clinical Relevance: Even though vaccine allergy occurs very rarely, a safe procedure for immunization can be applied, through specialized allergy consultancy, for most subjects with suspected allergy to vaccines, and who could be potentially excluded from vaccination for risk of adverse reactions.