Effectiveness and cost-effectiveness of pediatric rotavirus vaccination in British Columbia: A model-based evaluation

Background: Rotavirus gastroenteritis (RVGE) is associated with widespread morbidity and mortality in children worldwide. In high-income countries, including Canada, the burden of RVGE relates largely to morbidity and healthcare utilization. Two live rotavirus vaccines (RotaTeq^® (Merck Frosst Canada Ltd.) and Rotarix™ (GlaxoSmithKline Inc.)), are now approved for use in Canada, but their economic attractiveness has not been evaluated in the Canadian context. Methods: We performed a model-based economic analysis using a Markov chain Monte Carlo simulation of RVGE in populations of British Columbia children. Models were parameterized based on best available data on disease natural history and epidemiology, vaccine effectiveness and cost, and healthcare costs, and calibrated such that projections of healthcare utilization and vaccine coverage closely matched empirical estimates. Robustness of projections was evaluated in deterministic and probabilistic sensitivity analyses. Results: Based on the best available data, childhood immunization against RVGE was projected to prevent 63-81 infections per 100 children vaccinated, and to prevent substantial numbers of outpatient medical visits. It was projected that either vaccine would prevent 1-2 hospitalizations per 100 children immunized. Vaccination was projected to increase healthcare costs: immunization with Rotarix™ would prevent incident infections at a cost of approximately $10 per infection prevented or $2400 per quality-adjusted life-year gained. Vaccination with RotaTeq™ would be more costly and less effective and would not be preferred. Projections were robust in the face of wide-ranging sensitivity analyses. Interpretation: The use of currently available vaccines against RVGE in British Columbia children is projected to result in a substantial reduction in the burden of illness and healthcare utilization associated with RVGE, with a modest increase in healthcare costs. RVGE vaccination should be considered "highly cost-effective" relative to other commonly available health interventions.