  Millions of young people are not immunized in low- and middle-income (LMI)
countries because of low vaccine availability resulting from inefficiencies in
cold supply chains. We create supply chain network design and distribution
models to address the unique characteristics and challenges facing vaccine
supply chains in LMI countries. The models capture the uncertainties of demand
for vaccinations and the resulting impacts on immunization, the unique
challenges of vaccine administration (such as open vial wastage), the
interactions between technological improvements of vaccines and immunizations,
and the trade-offs between immunization coverage rates and available resources.
The objective is to maximize both the percentage of fully immunized children
and the vaccine availability in clinics. Our research examines how these two
metrics are affected by three factors: number of tiers in the supply chain,
vaccine vial size, and new vaccine technologies. We tested the model using
Niger's Expanded Program on Immunization, which is sponsored by the World
Health Organization. We make many observations and recommendations to help LMI
countries increase their immunization coverage.
