Are children with inborn errors of metabolism and cystic fibrosis adequately protected? Immunization status and seroepidemiological evaluation of vaccine-preventable diseases

OBJECTIVES: Inborn errors of metabolism (IEMs) are rare genetic disorders associated with increased vulnerability to infections and risk of metabolic decompensation. Although routine immunization is recommended, data on real-world vaccination status, seroprotection rates, and vaccine safety in children with IEMs remain limited. This study aimed to evaluate immunization status, antigen-specific seroprotection rates, determinants of seronegativity, and vaccine safety in a cohort of children with IEMs. METHODS: This single center cross-sectional study was conducted at a tertiary Pediatric Metabolism Unit of Eskişehir Osmangazi University between January and June 2022. A total of 169 children were included. Vaccination history was obtained from immunization cards and parental report. Serological protection was assessed using commercial immunoassays and interpreted according to assay-specific cut-offs. Age eligibility and time since last vaccine dose were analyzed. Descriptive statistics were used to summarize immunization coverage and antibody levels. Group comparisons were performed using chi-square or Fisher's exact tests for categorical variables and non-parametric tests for continuous variables. A p-value