Immunization programs in low-income countries are facing the most ambitious targets of the last four decades: reach every child with existing and many new vaccines. The original immunization supply chains (iSCs) design, put in place in the 1970’s, is struggling to exceed an 80% coverage rate and is unable to support the increasing volume, complexity, bulk, and cost of vaccines. In recent years, the iSC community has recognized the need to encourage more comprehensive iSC redesigns to address the changing requirements of immunization programs. These “next-generation” immunization supply chains represent a fundamental shift in how iSCs are designed and managed in low- and middle-income countries.
Next-generation supply chains are not defined by a specific design, but instead share a set of characteristics that represent a fundamental change in how EPI supply chains have historically operated. The purpose of a next-generation iSC is to improve product availability and ensure all children are reached with a full set of immunizations in a cost-effective manner. They are designed to embrace the five fundamentals of system design, data, people, cold chain equipment and continuous improvement to deliver immunization services reliably, efficiently and safely.
For those leading the change-management process in countries, evidence related to next-generation iSC is limited and not easily accessible. VillageReach compiled a list of critical questions regarding the impact of shifting to next-generation iSC from stakeholders at the country and global levels and used these questions to develop a research and evidence framework. Three broad themes were identified and these cover the “what”, “why” and “how” of next-generation iSCs.
VillageReach conducted a review guided by these key themes and found little evidence in the peer-reviewed literature linking holistic supply chain design or even individual supply chain improvements to improved outcomes. While the grey literature includes more evidence from LMICs, it is primarily related to the effect of supply chain improvements on commodity availability. However, a challenge is there is no single repository for these works, hence it is not easily accessible to advocates or key stakeholders.
Several themes arose from the literature review. First, documentation of the problem is strong. We found substantial evidence in the literature documenting the challenges experienced or anticipated with new vaccine introductions on the supply chain including; increase in cost, waste, reduced availability and the creation of bottlenecks. There is similar documentation around challenges with keeping the cold chain maintained at the right temperature, and the impact of vial size on storage and transport. Second, modeling is an important source of data. Modeling studies in peer-reviewed literature demonstrate the anticipated outcomes of supply chain improvements including improvements in availability and efficiency. Third, costing of existing systems is useful, but limited costing of improved systems exists. The EPI Costing (EPIC) studies are a rich source of information that identify cost drivers of EPI programs, including supply chain components; provide new insights into total cost and efficiency metrics; and help answer questions related to the cost of existing systems. Additional work is expected through the Immunization Delivery Cost (IDC) evidence project. Limited work has been done however, to evaluate the cost difference between current iSC and next-generation iSC systems. Fourth, grey literature does include evidence, particularly on availability of commodities. Case studies, supply chain partner reports, impact briefs, and blogs provide evidence of supply chain improvements for vaccines and other commodities. In particular, repositories are available from USAID|DELIVER and Project Optimize. The grey literature also provides more examples of holistic next-generation iSC impact. Some of the powerful examples we have found were from Nigeria, Senegal, Zambia, Mozambique and Benin (see detailed report attached).
While there is much discussion regarding the importance of evidence-based decision making, our work to date has highlighted that the existing literature does not answer many of the priority questions decision-makers are currently asking regarding the move to next-generation immunization supply chains. Moreover, some of the existing evidence is not easily accessed or interpreted by decision-makers. Finally, significant gaps exist regarding the process for move to a next-generation iSC and the resources required.