[Anaphylaxis to MMR vaccine gelatin : practical recommendations]

This article reports two pediatric cases of anaphylaxis to the M-M-RVaxPro® vaccine, attributable to porcine gelatin used as a stabilizer (14.5 mg/dose). Both patients developed severe reactions after the booster dose, with positive skin and blood tests for gelatin. The first case had hereditary alpha-tryptasemia as an aggravating factor. Investigations ruled out the responsibility of neomycin, latex, and chlorhexidine. Key recommendations include avoidance of gelatin-containing vaccines and medications, substitution with gelatin-free alternatives (Priorix®), evaluation of food tolerance through an oral challenge test, and provision of an emergency kit with epinephrine. Hospital monitoring is recommended for future vaccinations in patients with mast cell disorders. The study highlights gelatin as the primary culprit in vaccine anaphylaxis, emphasizing the importance of systematic testing for vaccine components and proper management of sensitized patients.