Humoral immunity 10 years after booster immunization with an adolescent and adult formulation combined tetanus, diphtheria, and 5-component acellular pertussis vaccine

► We examined protective responses 1, 3, 5, and 10 years after Tdap vaccination. ► In 99% of adolescents, anti-diphtheria and anti-tetanus antibodies lasted 10 years. ► Seropositivity to ≥1 pertussis antigen persisted in most adolescents for 10 years. ► Adults responded to Tdap similarly to adolescents. ► Ten years is a reasonable interval for a Tdap vaccine booster dose.