The Decade of Vaccine Economics (DOVE), housed at Johns Hopkins University, aims to generate economic evidence on vaccine impact in low- and middle-income countries (LMICs). The project began in 2011 and is in its fourth phase. Phases I-III focused on building economic models to estimate the cost of illness, return-on-investment, and the cost of financing vaccine programs. Phase IV aims to expand on previously developed economic models by updating the estimate of the return-on-investment (ROI) of vaccines. Additional DOVE IV projects include collecting primary data on the cost of illness in two LMICs, reviewing existing data on the cost of vaccine-preventable diseases, and piloting contingent valuation methods in Bangladesh.