Effective and secure transport arrangements should be in place for moving vaccines keeping the correct temperatures. The process can be defined in 5 steps:
- Assessing the shipment conditions.
- Deciding the suitable means for vaccine transportation.
- Preparing the shipment.
- Reception and Cold chain verification.
When opening new distribution channels or recurrent cold chain breaks are experienced in current distribution, qualifying transport routes is recommended. The process typically involves monitoring worst-case routes in order to ensure that the personnel and the chosen equipment and packaging arrangements are able to maintain acceptable transport temperatures even in such cases. Guidance on how to carry out a study of this kind is given in the WHO document Study protocol for temperature monitoring in the vaccine cold chain.
Assessing Shipping Conditions
To calculate the volume of vaccine to be shipped, it is necessary to know for each vaccine and diluent in the shipment:
- The required storage temperature: 3 ranges of temperature are normally considered for vaccine transportation: -15 to -25°C, +2 to +8°C or ambient;
- The number of doses to be transported;
- The packed volume per dose (cm3/dose). The packed volume includes the vaccine vial, the packet containing the vaccine vial and any intermediate packaging (secondary packaging).
The maximum recommended packed volume per vaccine dose and diluents are:
Be aware that the volume obtained from multiplying the packed volume per dose by the number of doses only takes into consideration the primary and the secondary packages: it doesn’t include the cold box packaging. Estimating the final transport volume (including the cold box) is necessary to correctly plan the transport means. For this purpose, a transport box bulking factor can be used. The bulking factor depends on the type of vaccine. WHO Guideline for establishing or improving primary and intermediate vaccine stores, recommends the following transport box bulking factors:
- BCF, OPV, measles, MMR, MR = 6.0
- Other vaccines = 3.0
- Diluent, droppers = 1.5
Evaluating the Journey
To evaluate the journey, some of the criteria to be consider are:
- The transport modes and vehicle types.
- The journey distances and its expected duration.
- The environmental conditions: temperature (day–night and seasonal temperature extremes) and geographical and natural hazards.
There are 3 basic transportation stages in the supply chain of vaccines:
- From the manufacturer to a primary or central store: usually international shipments.
- Between (intermediary) stores: normally between national or district store facilities and down to the health care facility.
- Outreach transportation: final vaccine delivery during regular EPI or to a vaccination site during a mass vaccination campaign.
Aerial or terrestrial modes are preferred for vaccine transportation. Air transport is usually chosen for international or long-distance shipments. Terrestrial is used for transport of vaccine within the same country. Outreach is often done by any land transport mode: car, motorcycle, bicycle. Because of the long duration of the journeys, vaccines are rarely transported through waterborne means.
For further information on how to design a vaccine distribution system, refer to WHO Guideline for establishing or improving primary and intermediate vaccine stores.