Assessing adolescent immunization options for pertussis in Canada: A cost-utility analysis

Area of Science:

• Public Health
• Epidemiology
• Health Economics

Background:

• Adolescent tetanus, diphtheria, and pertussis (Tdap) immunization is crucial for preventing pertussis.
• The timing of Tdap vaccine administration significantly impacts disease prevention and associated costs.
• Assessing cost-utility of different adolescent Tdap immunization schedules is vital for Canadian healthcare policy.

Purpose of the Study:

• To evaluate the cost-utility of various adolescent Tdap immunization strategies in Canada.
• To compare the economic impact of immunizing at age 10, age 14 (status quo), or removing adolescent vaccination.
• To inform optimal Tdap vaccination policies for adolescents.

Main Methods:

• A cost-utility analysis using a Markov model simulating pertussis disease progression in adolescents (starting at age 10).
• Comparison of three strategies: 10-year-old immunization, 14-year-old immunization (status quo), and no adolescent vaccination.
• Analysis from a healthcare payer perspective over a lifetime horizon, with a 1.5% discount rate for costs and outcomes.

Main Results:

• The current strategy of immunizing 14-year-olds yielded 40.44 QALYs and cost $26.28 per individual.
• Immunization at age 10 dominated the 14-year-old strategy and was cost-effective compared to no immunization (ICER $74,899/QALY).
• Removing adolescent vaccination was the most cost-effective strategy in 78% of simulations at a $50,000/QALY threshold, with sensitivity analyses highlighting pertussis incidence and severity as key factors.

Conclusions:

• Alternate adolescent Tdap vaccination strategies, specifically immunization at age 10 or removal of the adolescent vaccine, are more cost-effective than the current practice of immunizing at age 14.
• These findings support policy considerations for optimizing adolescent Tdap immunization schedules in Canada.
• The analysis assumes concurrent recommendation of maternal Tdap immunization.