The projected cost-effectiveness and budget impact of Alternative HPV Vaccines in Senegal: A Modelling Study

Abstract

Abstract 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 national immunization program using a two-dose Gardasil-4 schedule for 9-year-old girls. As Senegal approaches transition from Gavi support, full procurement costs will shift to the government, necessitating evidence-based decisions about the most cost-effective vaccination strategies going forward. This study evaluates the health and economic value of alternative HPV vaccination options to inform sustainable and equitable national policy. Methods We used a static cohort model to assess the cost-effectiveness and budget impact of 23 HPV vaccination strategies varying by vaccine type (Gardasil-4, Gardasil-9, Cervarix, Cecolin), dose number (one vs. two), and coverage level (current, 70%, WHO target). The analysis simulates health and cost outcomes for 9-year-old girls vaccinated annually from 2019 to 2035. Outcomes included cervical cancer cases, deaths, and disability-adjusted life years (DALYs) averted. Costs were evaluated from a government perspective in 2023 USD, with a 3% discount rate applied. Input parameters were derived from GLOBOCAN 2020, peer-reviewed 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, consistently yielded the most favorable cost-effectiveness ratios. Gardasil-9 offered the greatest absolute health benefits (up to 112,866 DALYs averted) but required significantly higher programmatic investments, limiting its cost-effectiveness unless vaccine prices were reduced. Five strategies mainly involving Cecolin and one-dose Gardasil-9) were efficient under national willingness-to-pay thresholds. At lower thresholds, such as 7% of GDP per capita or USD 100, one-dose Cecolin with 90% coverage was optimal. Conclusion HPV vaccination remains a highly cost-effective intervention in Senegal across multiple scenarios. Cecolin-based strategies, especially one-dose regimens, offer a scalable and economically attractive approach post-Gavi. Gardasil-9 could be viable with substantial price reductions. As Senegal prepares for Gavi transition, aligning vaccine choice with both cost-effectiveness and implementation feasibility will be essential to ensuring long-term program sustainability and equitable health outcomes.