Hypersensitivity reactions to the Sabin vaccine in children with cow's milk allergy.

BACKGROUND: The Sabin vaccine is used world-wide, and most children with food allergies receive it without incident. However, in the 2009 vaccination campaign conducted in Argentina, four children experienced immediate-type hypersensitivity reactions following vaccination. OBJECTIVE: We aimed to review the medical history of the affected children, study their allergic condition after the episodes and analyse the presence of allergenic vaccine components. METHODS: Patients were selected based on their immediate allergic reactions following vaccination. They were assessed for allergies to cow's milk and hen's egg. The presence of cow's milk proteins in the vaccine was tested by various immunoassays involving cow's milk- or α-lactalbumin-specific polyclonal rabbit antiserum and patient sera. RESULTS: All of the patients had a history of milk allergy, and no history or current evidence of egg hypersensitivity was found. Levels of cow's milk- and Sabin vaccine-specific IgE were increased, and the result of a skin prick test with cow's milk proteins or the Sabin vaccine was positive in each patient. In addition, an ELISA using specific rabbit antiserum detected α-lactalbumin in the Sabin vaccine. When α-lactalbumin was employed as a soluble inhibitor in a competitive ELISA, binding to vaccine-coated plates by cow's milk- or α-lactalbumin-specific rabbit antiserum or by patient serum containing IgE was inhibited. CONCLUSIONS: We have demonstrated that these patients were allergic to cow's milk, and had circulating and mast cell-bound IgE antibodies specific to cow's milk proteins. We found that the Sabin vaccine contained α-lactalbumin, which may have been responsible for the reactions elicited following vaccination with the Sabin and dual viral vaccines in combination.

Alergia al huevo en Pediatría. Documento del Comité de Pediatría de la Asociación Argentina de Alergia e Inmunología Clínica / Egg allergy in pediatrics. Pediatric Committee document of the Argentina Association of Allergy and Clinical Immunology

El huevo de gallina es una fuente de proteínas de alto valor biológico de bajo costo y de vitaminas del complejo B, importantes para la alimentación del niño. Culturalmente es uno de los alimentos básicos de nuestra dieta y, debido a esto, la alergia a sus proteínas es una de las más frecuentes en la infancia y tiene su mayor impacto en niños en edad preescolar. Estos niños representan una población vulnerable debido a que se encuentran en una etapa importante de su crecimiento y desarrollo, y el tratamiento de esta patología genera la adopción de dietas restrictivas que pueden impactar en forma negativa en su salud y calidad de vida. Este impacto está dado en parte por la ubicuidad de sus proteínas, que limita ampliamente la dieta y genera riesgos de reacciones alérgicas que se incrementan a medida que el niño crece y alcanza una mayor independencia. Teniendo en cuenta la importancia de esta patología, el Comité de Pediatría realizó una revisión actualizada con el fin de proveer herramientas útiles para el manejo adecuado de la misma. (AU)

Eggs are a source of low cost high biological value protein and complex B vitamins important for the child's nutrition. Culturally it is one of the staples of our diet and because of this, egg allergy is one of the most common food allergies in childhood and has its greatest impact on preschool children. These children represent a vulnerable population because they are at an important stage in their growth and development and the treatment of this condition generates the adoption of restrictive diets that may impact negatively on their health and quality of life. This impact is given in part by the ubiquity of their proteins that largely restrict the diet and generates risks of allergic reactions that increase as the child grows and earns greater independence. Given the importance of this issue the Pediatrics Committee conducted an updated review to provide useful tools to manage this condition.(AU)