Title : Transforming vaccines access through cost-efficient last-mile delivery models in LMICs
Abstract:
Background:
In low? and middle?income countries (LMICs), persistent vaccine stockouts at the last mile hinder routine immunization (RI) coverage and exacerbate zero?dose burdens, particularly in hard?to?reach areas. Traditional ‘pull’ distribution models often require health workers to leave facilities to collect vaccines, leading to service disruptions, out?of?pocket expenses and inequitable access. Between 2019 to now (2025) Kenya, Uganda and Cameroon piloted cost?efficient Last Mile Delivery (LMD) models that shifted vaccine transport responsibility to sub?national teams, integrated supervision into deliveries and optimized ordering and routing.
Approach:
In Kenya, CHAI partnered with the National Vaccines and Immunization Programme to pilot LMD in three counties, pairing scheduled sub?county deliveries with optimized ordering cycles. Uganda tested integrated transport for vaccines and other health commodities in high zero?dose districts. Cameroon’s Expanded Program on Immunization piloted LMD in four diverse districts (urban, rural and security?compromised), replacing monthly pull?based collections with direct facility deliveries and on?site formative supervision. Mixed?methods evaluations combined routine logistics data, cost analysis and stakeholder interviews to assess changes in stock availability, timeliness and expenditure. Cost analyses captured pre? and post?pilot expenditures including out?of?pocket costs previously borne by health workers.
Findings/Results
Across countries, LMD substantially reduced stockouts and improved supply chain reliability.
Kenya:
• Facility?reported stockouts dropped by ~50% and prolonged stockouts (>28 days) by ~57%.
• Distribution costs from sub?national stores to facilities fell by 61–79%.
• Pre?pilot, 52% of vaccine collection costs were paid out?of?pocket by health workers under LMD, this burden was eliminated, though some costs shifted to government budgets.
Uganda:
• Integrated delivery reduced ad?hoc trips, improved cold chain utilization, and freed staff time for service delivery.
• Cost modelling suggested savings when commodity integration was maximized, with potential to reallocate resources toward performance monitoring.
Cameroon:
• Adequate stock levels rose from 41% to 58%, stockouts fell from 38% to 23% and delivery timeliness exceeded 99%.
• The average cost per vaccinated child was ~47 FCFA, with an incremental cost of ~242 FCFA per additional child reached highly efficient given geographic and security challenges.
• Integration of other health products such as oxytocin during LMD further optimized delivery rounds.
Common enabling factors included predictable delivery schedules, embedded supervision and improved data use for ordering and allocation. Barriers included limited vehicles, road inaccessibility and perceptions among policymakers that LMD increases costs, largely due to unaccounted pre?pilot out?of?pocket spending.
