Economic evaluation of an extended acellular pertussis vaccine programme for adolescents in Ontario, Canada.

Purpose: Pertussis is a frequent cause of cough illness in adolescents. In Canada, until recently immunization against pertussis in public programmes has been restricted to children under the age of 7. The purpose of this analysis was to estimate the health and economic impact of an additional booster dose of the acellular vaccine in adolescents in Ontario.

Methods: We performed a cost effectiveness analysis, based on a predictive spreadsheet dynamic model following a cohort of 144,000 adolescents in Ontario from the age of 12 years over a 10-year-period from the Ontario Ministry of Health (MoH) and societal perspectives. The model was used to compare costs and benefits of a combined vaccination programme (CVP) including tetanus, diphtheria, and acellular pertussis (dTacp) administered at age 12, compared to current practice.

Results: From the MoH perspective, booster vaccination of dacpT at 12 years via the CVP would produce a yearly additional expected cost of CAD $0.52 per adolescent in Ontario with an incremental cost-effectiveness ratio of CAD $168 per pertussis case avoided based on a 10-year-period. If outcomes are discounted at 3%, the incremental cost-effectiveness ratio rises to $188/discounted pertussis case avoided. From the societal perspective, the CVP would be cost saving CAD $858,106 at 10 years for the cohort. Over the 10-year-period, more than 4400 cases of pertussis would be prevented with approximately 50 hospital admissions averted.

Conclusions: This study suggests that administering a booster dose of dTacp at 12 years of age to replace diphtheria and tetanus vaccination at 14 years may reduce the economic burden of pertussis treatment in the long term at a reasonable cost.