Corrigendum to 'Antibody persistence and safety and immunogenicity of a second booster dose nine years after a first booster vaccination with a reduced antigen diphtheria-tetanus-acellular pertussis vaccine (Tdap) in adults'. [Vaccine 36 (2018) 6325-6333]

•In vaccinated adults, pertussis antibody levels wane over time, but a Tdap dose boosts immunity.•Diphtheria and tetanus seroprotection rates were high 5 (≥98.0%) and 9 (≥98.1%) years post-initial vaccination.•Nine years post-vaccination, ≥84.9% of participants were seropositive for pertussis antigens.•A dose of Tdap administered 9 years post-primary dose was immunogenic and well-tolerated.