Safety of MMR vaccination evaluated in children with food and gelatin allergy in Iran.

Abstract

Background: Vaccination is essential for building immunity across various populations, and governments consider it a cornerstone of public health. This study aims to investigate the prevalence of gelatin allergy among infants with food allergies who have received previous vaccinations and were referred to this center for Measles-Mumps-Rubella (M.M.R.) vaccine administration.

Methods: This study, conducted at the Immunology Children's Medical Center (CMC) Hospital in Tehran, Iran, aimed to explore the prevalence of gelatin allergy in infants with food allergies undergoing M.M.R vaccine injections. The cross-sectional study included children diagnosed with food allergies, confirmed by allergy specialists, and who provided consent. The methodology involved different tests based on the severity of food allergies. For children with mild food allergies, a gelatin prick test preceded MMR vaccination. Those with severe food allergies or a history of vaccine reactions underwent skin prick tests with various gelatins and the MMR vaccine. Positive results led to graded dose vaccinations. Data, including clinical questions, were recorded using a standard vaccination questionnaire.

Results: Results from 163 evaluated children (average age: 16.85 months) revealed that 8% were allergic to gelatin. Notably, all gelatin-allergic patients had a positive family history of atopia. A significant association existed between gelatin allergy and a positive intradermal vaccine test. No significant relationships were found with gender, age, food allergens, infant milk type, antihistamine use, blood history, or product use.

Conclusion: The study concludes that a gelatin-free vaccine is preferable for allergic patients. In cases where such a vaccine isn't available, a skin test with the vaccine is recommended before full-dose administration. The findings emphasize the importance of considering family history and intradermal vaccine tests in managing gelatin allergies during vaccinations.