The impact of adolescent pertussis immunization, 2004–2009: lessons from Australia

To compare the impact of three strategies for delivering a booster dose of adult-formulated tetanus–diphtheria–pertussis (Tdap) vaccine to adolescents in Australia. These comprise: (i) administering Tdap to: a one-year age cohort; (ii) administering Tdap to the entire high school and to subsequent entrant cohorts; and (iii) administering Tdap to the entire high school but without continuing to immunize entrant cohorts.