Question: What is the duration of continued seroprotection of diphtheria vaccination (≥10 years) conveyed by a specific schedule of diphtheria toxoid (- containing) vaccination which is comprised of at least 3 vaccine doses (primary series) and 3 booster doses until adulthood.
- Population: Immunocompetent children and adults.
- Intervention: Vaccination with diphtheria toxoid (-containing) vaccination.
- Comparison: No vaccination, or different duration between vaccination and serological testing.
- Outcome: Diphtheria serum antibody levels/ seroprevalence.