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

Children with inborn errors of metabolism demonstrated high overall vaccination coverage and reassuring safety profiles when immunized during metabolically stable periods.

Observed immunity gaps were largely explained by programmatic factors, age eligibility, and time since vaccination.

These findings support systematic vaccination review and selective serological assessment within routine metabolic follow-up while avoiding overinterpretation of seronegativity as disease-specific immune insufficiency.