The projected cost-effectiveness and budget impact of alternative HPV vaccines in Senegal: A modeling study

Background: Cervical cancer remains a leading cause of morbidity and mortality among women in Senegal. In 2018, with support from Gavi, Senegal introduced HPV vaccination into its immunization program using a two-dose Gardasil-4 schedule for 9-year-old girls. As Senegal approaches transition from Gavi support, full vaccine procurement costs will shift to the government, necessitating evidence-based decisions on the most cost-effective vaccination strategies. This study evaluates the health and economic value of alternative HPV vaccination options to inform sustainable and equitable policy. Methods: A static cohort model assessed the cost-effectiveness and budget impact of 23 HPV vaccination strategies varying by vaccine type (Gardasil-4, Gardasil-9, Cervarix, Cecolin), dose number (one versus two), and coverage level (current, 70%, WHO target). Health and cost outcomes were simulated for 9-year-old girls vaccinated annually from 2019 to 2034. Outcomes included cervical cancer cases, deaths, and DALYs averted. Costs were evaluated from a government perspective in 2022 USD, applying a 3% discount rate. Input parameters were from GLOBOCAN 2020, literature, and national data. Sensitivity analyses explored uncertainty around key assumptions. Results: All HPV vaccination strategies were cost-effective under a willingness-to-pay threshold of 30% of GDP per capita (USD 450 per DALY averted). Cecolin-based strategies, particularly one-dose schedules with expanded coverage, yielded the most favorable cost-effectiveness ratios. Gardasil-9 offered the greatest health benefits (up to 112,866 DALYs averted) but required higher programmatic investments, limiting cost-effectiveness unless prices decreased. Five strategies, mainly Cecolin and one-dose Gardasil-9, were efficient under national thresholds. At lower thresholds, such as 7% of GDP per capita (USD 100), one-dose Cecolin with 90% coverage was optimal. Conclusion: HPV vaccination in Senegal is highly cost-effective. Cecolin one-dose strategies offer a scalable, affordable approach post-Gavi transition, while Gardasil-9 is viable only with price reductions. Aligning vaccine choice with cost-effectiveness and feasibility is essential for long-term sustainability and equitable health outcomes.