Potential Cost Impact in the Netherlands Due to Different Waning Patterns of Cervical Cancer Vaccines

Abstract

Background: Cervical cancer vaccines are now available. Since some uncertainty regarding their HPV type-specific antibody waning profiles exists, we examined the clinical and economic impact of different waning scenarios in the Netherlands. Methods: A Markov cohort model, populated using Netherlands epidemiological, cervical cancer screening, treatment pattern, and cost data was used to perform the analysis. Societal lifetime costs were included at 2006 prices. Initial vaccine efficacy of 95% against HPV-persistent infection with HPV-16/18 plus 30% efficacy against other oncogenic HPV types (“cross-protection”) was assumed in the base case. Reduction in cancer cases, associated quality-adjusted life years (QALYs) and costs for a vaccine against HPV-16/18, and other oncogenic HPV types with lifetime cervical cancer protection were compared with vaccine scenarios having less than lifetime protection. These scenarios included: 1) alternative combinations of HPV types that wane (HPV-18 alone, oncogenic non-vaccine HPV alone, HPV-18 + oncogenic non-vaccine HPV); 2) alternative durations of protection (range: 5–30 years); 3) alternative patterns representing the time of decline to 0% protection (linear 5-year, linear 10-year, other); 4) alternative rates of booster vaccine coverage (range 0% - 100%) and protection (i.e. double original vaccine protection vs. lifetime protection) Results: In the hypothetical vaccine scenarios, overall duration of vaccine protection had the largest impact, followed by HPV-type-specific waning, then the pattern of waning decline. Waning impact depended on the relationship between age and HPV infection rate, as well as on HPV-type distribution in cervical cancer. Adding a booster increased the overall costs, but improved clinical outcomes and QALYs. Conclusion: Vaccine waning is an important characteristic to consider when assessing a vaccine's effectiveness against cervical disease related morbidity and mortality; a vaccine with more sustained protection is predicted to have better clinical outcomes at lower total costs.