Randomized trial data on the comparative effectiveness of alternative vaccine and dose regimens is necessary. Public health policy makers also require information on the projected cost and long-term health outcomes associated with each vaccine regimen to make evidence- based decisions regarding the large-scale implementation of sustainable, cost-effective HPV vaccination programs. Mathematical simulation models of cervical carcinogenesis can integrate biologic, epidemiologic, economic, and behavioral data from the 1DT and other studies to project the long-term health and economic impact of different vaccine and dose regimens and evaluate the comparative- and cost-effectiveness of alternative vaccination strategies to inform public health policy. Optimal implementation policies may depend on the level and duration of efficacy for a single dose and achievable completion rates for a two-dose regimen. Even if one- dose protection is found to be lower than protection associated with two or three doses, the relative costs and effects of vaccinating more individuals with one dose might yield a greater reduction in cervical cancer incidence and mortality. We will use mathematical models to quantify the potential tradeoffs between resource utilization, simplicity of implementation and administration, and program effectiveness based on real-world data on intervention costs and effectiveness.