Figure 1. Schematic describing vaccine flow-down through the immunization system.

Notes:

a. Each color represents a supply shipment as it moves through the immunization system.

b. Each box represents routine vaccine doses to immunize the target population in one month, except reserve stock boxes at the health facility level which represent routine vaccine doses for 0.5 months.

c. Resupply occurs every three months at national, regional, and district levels, and monthly at the health facility level.

d. Reserve stock (excess supply in case of increased demand or stock outs) is three months at the national level, one month at regional and district levels, and 0.5 months at health facility level.

e. Vaccines stored at the national level use tertiary packaging volumes while vaccines stored at subnational levels use secondary packaging volumes.

f. This schematic does not depict stock rotations which would preferentially use vaccines received earlier.