The Economics of Ebola Virus Disease

Abstract

Background: Ebola virus disease (EVD) continues to threaten public health globally, disproportionately more so in the low- and middle-income countries (LMICs) of Africa. The enormous burdens of EVD have led to extensive research into prevention and control and triggered significant investments from the global community. There still exists a gap in terms of resource generation and management for addressing this disease, as well as a consequent urgent need for evidence-based economic decision making.Objectives: The work reported in this thesis aimed to synthesize evidence on EVD economic evaluations and to conduct economic evaluations of an EVD vaccine in LMICs. This thesis is built around three studies: (1) a scoping review to identify, characterize, and evaluate published studies involving the economic evaluation of EVD; (2) an economic evaluation using a dynamic transmission model of EVD to assess the cost-effectiveness analysis of an EVD vaccine and vaccination program in a hypothetical population of 1000 using data from an EVD outbreak in selected countries in Africa; and (3) a comparative economic evaluation to examine value-based pricing of an EVD vaccine in Central and West African countries with prior EVD outbreaks. We used a dynamic transmission model to evaluate the cost-effectiveness and a value-based price (VBP) of an EVD vaccine Methods: From eligible studies retrieved using multiple databases, we summarized the impact and economics of EVD, assessed economic studies to date, identified unanswered questions for further exploration, and made recommendations for future EVD economic studies with a special focus on LMICs. Using a modified SEIR (Susceptible, Exposed, Infectious, Recovered, with Death added [SEIR-D]) model that accounted for death and epidemiological data from an EVD outbreak in selected countries (Democratic Republic of Congo, Liberia, Sierra Leone, Uganda), we modeled the transmission of EVD in a hypothetical population of 1000. With our model, we estimated the cost-effectiveness of an EVD vaccine and an EVD vaccination intervention. Based on the cost-effectiveness metrics and using willingness-to-pay thresholds equal to varying percentages of the Gross Domestic Product (GDP) per capita, we demonstrated how a VBP is calculated using an adaptation of the “QALY-capped” approach. Results: Twenty-six studies were retrieved which focused on the cost/burden of EVD, willingness-to-pay for EVD vaccine, cost of preparedness of EVD treatment centers, and funding for EVD. The impact of EVD was estimated to be substantial in terms of human and fiscal loss. Vaccinating the population at risk to the herd immunity threshold was estimated to avert about 99% of infections, deaths, and disability adjusted life years (DALYs). Although vaccination resulted in incremental costs in the countries evaluated, it was found to be cost-effective in all cases given resultant decrements in outcomes that offset the accumulated costs. Cost-effectiveness was determined to be directly proportional to transmission rate – being more cost-effective in settings with higher transmission rates. The VBP for the vaccine is directly proportional to both cost-effectiveness and GDP per capita- with higher cost-effectiveness and higher GDP per capita resulting in higher price ceilings compared to lower cost-effectiveness and lower GDP. Conclusions: The severe impact of EVD puts pressure on governments and the international community for better resource utilization and re-allocation. From the payer perspective, vaccination against EVD is cost-effective. Despite the concerns with the “QALY-cap” approach, we illustrated that it is an easily comprehensible method for determining the VBP of a vaccine using a cost-effectiveness analysis. There is an urgent need for territory-specific evidence-based economic plans and economic evaluation of mitigations to enhance resource allocation for EVD prevention and treatment.