Augmenting Transport versus Increasing Cold Storage to Improve Vaccine Supply Chains

Abstract

BackgroundWhen addressing the urgent task of improving vaccine supply chains, especially to accommodate the introduction of new vaccines, there is often a heavy emphasis on stationary storage. Currently, donations to vaccine supply chains occur largely in the form of storage equipment.MethodsThis study utilized a HERMES-generated detailed, dynamic, discrete event simulation model of the Niger vaccine supply chain to compare the impacts on vaccine availability of adding stationary cold storage versus transport capacity at different levels and to determine whether adding stationary storage capacity alone would be enough to relieve potential bottlenecks when pneumococcal and rotavirus vaccines are introduced by 2015.ResultsRelieving regional level storage bottlenecks increased vaccine availability (by 4%) more than relieving storage bottlenecks at the district (1% increase), central (no change), and clinic (no change) levels alone. Increasing transport frequency (or capacity) yielded far greater gains (e.g., 15% increase in vaccine availability when doubling transport frequency to the district level and 18% when tripling). In fact, relieving all stationary storage constraints could only increase vaccine availability by 11%, whereas doubling the transport frequency throughout the system led to a 26% increase and tripling the frequency led to a 30% increase. Increasing transport frequency also reduced the amount of stationary storage space needed in the supply chain. The supply chain required an additional 61,269L of storage to relieve constraints with the current transport frequency, 55,255L with transport frequency doubled, and 51,791L with transport frequency tripled.ConclusionsWhen evaluating vaccine supply chains, it is important to understand the interplay between stationary storage and transport. The HERMES-generated dynamic simulation model showed how augmenting transport can result in greater gains than only augmenting stationary storage and can reduce stationary storage needs.

Economic impact of thermostable vaccines

“…Our team used our previously described HERMES (Highly Extensible Resource for Modeling Event-Driven Supply Chains) software to construct and run detailed discrete-event simulation models of the Expanded Program on Immunization (EPI) and Universal Immunization Program (UIP) supply chains (representing all vaccines, storage and immunization locations, storage devices, vehicles, ordering and shipping policies and processes, and associated costs) for the Republic of Benin[4, 5] (4 levels: 1 national store, 7 region/department stores, 80 communes, 763 health posts); the state of Bihar, India[5] (4 levels: 1 state store, 7 division stores, 13 of 38 district stores, 161 of 533 PHCs); and Niger[1, 3, 6, 7] (4 levels: 1 national store, 7 regional stores, 42 districts, 644 integrated health centers).…”

“…However, many vaccine supply chains in low- and middle-income countries have shortages in refrigerated (or even lower temperature) storage and transport capacity to accommodate all of the vaccine doses that must eventually make it to the population. [2, 3] Making certain vaccines thermostable would allow these vaccines to be stored outside refrigerators or freezers, thus freeing up space for vaccines that still require cooler or cold temperatures. More vaccine doses reaching the population can protect more mothers and children from infectious diseases, thus saving medical costs and productivity losses.…”

The impact of introducing new vaccines on the health system: Case studies from six low- and middle-income countries

“…There is a lack of research focusing on the impact of new vaccine introductions on countries' expanded programme of immunisation (EPI) or health system as a whole, particularly in low-income countries [3,4]. Previous research has typically focused either on the impact of vaccination campaigns on the routine immunisation service [5][6][7][8], or the impact of new vaccine introductions on specific elements of the health system, such as cold chain [9], logistics and supply [10,11] or coverage [12].…”

Economics and financing of vaccines for diarrheal diseases

“…92 Moreover, the cost of vaccine delivery in middle and low income countries should not be overlooked, as large new vaccines such as rotavirus can lead to bottlenecks that inhibit the delivery of other vaccines. [93][94][95] Evaluating the economics of vaccines for nearly all types of diarrheal diseases bring particular common challenges. Since many episodes of diarrheal diseases go undiagnosed, burden may be underestimated or mistakenly ascribed to the wrong causes or pathogens.…”