Economic evaluation of an extended acellular pertussis vaccine program for adolescents in Québec, Canada

Pertussis is a frequent cause of cough illness in adolescents. In Canada, immunization against pertussis in public programs has been restricted to children under 7 years of age. 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 Québec.

We performed a cost-effectiveness analysis, based on a predictive spreadsheet dynamic model following a cohort of 90,929 adolescents in Québec from the age of 14 years over a 10-year period from the Québec Ministry of Health (MOH) and societal (SOC) perspectives. The model was used to compare costs (2003 values) and benefits of an adolescent vaccination program (AVP), including a diptheria, tetanus, and acellular pertussis (dTacp) vaccine administered at age 14 years, with current practice.

From the MOH perspective, a booster vaccination of dTacp at age 14 years via the AVP would produce a yearly additional expected cost of Can dollars 1.06 per adolescent with an incremental cost-effectiveness ratio (ICER) of Can dollars 480 per pertussis case avoided based on a 10-year period. When outcomes are discounted at 3%, the ICER rises to Can dollars 527 per discounted pertussis case avoided. From the SOC perspective, the AVP would cost Can dollars 0.83 per adolescent per year with an additional cost per avoided pertussis case of Can dollars 377 (Can dollars 414 per additional discounted case of pertussis avoided). Over the 10-year period, 2012 non-discounted cases of pertussis would be prevented with approximately two hospital admissions averted.

This study suggests that administering a booster dose of dTacp at age 14 years to replace the diptheria and tetanus vaccination will slightly increase the economic burden from MOH and SOC perspectives; however, the number of pertussis cases and the number of hospital admissions will decrease.