E004: Cold boxes and vaccine carriers

The category E004 includes cold boxes, vaccine carriers and other passive insulated containers used for the transport of vaccines. Passive devices are non-powered devices that use ice-packs to cool the vaccine compartment.

Details regarding the products included in each sub-category of E004, as well as guidelines, performance specifications and verification protocols for this category, can be accessed through the drop-down sections below.

E004.1: Choosing a cold box or vaccine carrier

End-users of insulated containers and their procurement agents are advised to consider the following points when choosing vaccine storage equipment from this category:

Vaccine storage capacity: Vaccine storage capacity of each product is detailed on the individual product data sheets. The quantity and type of vaccine that requires transportation will be determined by the intended programmatic use of the cold box or vaccine carrier. Further guidance on the selection of passive containers can be found in the WHO Vaccine Management Handbook How to use passive containers and coolant-packs for vaccine transport and outreach operations.

Freeze-preventive products:

Freeze-preventive vaccine carriers should be considered for Expanded Programmes on Immunization (EPIs) that employ a frozen water pack policy (FWP). Freeze-preventive vaccine carriers protect vaccines from being exposed to freezing temperatures, they do not require icepack conditioning and they maintain a long cold life. (Cold life is measured from the moment when the container lid is closed until the temperature of the warmest point in the vaccine storage compartment first reaches +10°C, at a constant ambient temperature of +43°C.) Freeze-preventive

cold boxes are being developed that should offer similar advantages. Storage volume may however be reduced in these products due to the addition of a freeze-prevention barrier between the icepacks and vaccines.

Cold/warm life: Three types of cold/warm life are included on the product data sheets, which indicate for how long a cold box or vaccine carrier maintains a safe storage temperature during transport.

cold life with frozen icepacks
cool life with cool water-packs
warm life with warm water-packs.

Further guidance on the selection and use of coolant-packs can be found in the aforementioned WHO Vaccine Management Handbook "How to use passive containers and coolant-packs for vaccine transport and outreach operations".

Weight: Vaccine carriers are designed for a maximum fully loaded weight of 8 kg or less, and for cold boxes of 50 kg or less. However, in practice the maximum acceptable loaded weight is determined by how the box will be transported: by vehicle; by animal; by bicycle; or by hand. For health and safety reasons a worker should not be asked to lift a load greater than 25 kg and some workers may find this load excessive. Larger cold boxes may require two people to lift.

Durability: End-users and procurement agents should consider the conditions to which the insulated container will be exposed. Durability may be more important than weight for a container transported by vehicles over rough roads. The reverse applies to hand-carried boxes where weight and carrying comfort may be more important. Vaccine carriers are either constructed with a hard-plastic exterior, or with a soft canvas/PVC bag around the insulated walls. Experience has shown that the soft, canvas-type carriers have a shorter life-span; they are liable to wear and tear given environmental conditions and the catches and straps also tend to disintegrate over time. A warning about their short working life is included in the data sheets. Back-pack vaccine carriers are now available, and additionally, confer ergonomic advantages.

Foaming agent: Products which use cyclopentane as the insulation foaming agent are environmentally preferable to products that use R141b. Products containing CFCs are no longer acceptable under WHO PQS standards for prequalification.

Water-packs: Before placing an order, check that water-packs are included. If they are not included, select the appropriate water-pack model that will fit the chosen insulated container and order them at the same time. The product data sheets specify how many and which water-packs models are required. Consider ordering two sets so that one set can be frozen, or cooled, while the other set is in use.

Water-pack standardization: Wherever possible, try to purchase cold boxes and vaccine carriers which use just one size of water-pack and use these across the entire programme. This simplifies distribution management and prevents the use of water-packs which are not designed to fit the available cold boxes and vaccine carriers.

Cost: Insulated containers are bulky and shipping costs can often represent a high proportion of the total delivered price. Consider both the purchase price (EXW) and the shipping cost before making a final decision. Choose a product that fulfils programme requirements at the lowest cost.

Optional accessories: Some insulated containers may be offered with optional accessories, such as alternative carrying straps or backpacks, which may in some cases be costed in addition to the equipment: check this with the supplier and procurement agent at the time of procurement.

E004.2: Cool water-packs and warm water-packs

Cool water packs completely eliminate the risk of freezing freeze-sensitive vaccines, but they have a shorter period of safe storage compared to frozen packs. Correctly used, they do not cause a significant loss of potency due to heat exposure. Warm water-packs can be used to protect vaccines against freeze damage during transport in very cold climates.

Further guidance on the use of cool and warm water-packs can be found in the WHO Vaccine Management Handbook How to use passive containers and coolant-packs for vaccine transport and outreach operations.

E004.3: Keeping vaccines cool during immunization sessions

A number of vaccine carriers are supplied with a foam pad insert. This serves as a temporary lid to keep vaccines cool, whilst at the same time providing a surface to hold and protect vaccine vials during immunization sessions. The insert is a simple piece of soft foam which fits tightly inside the "neck" of the carrier on top of the icepacks and below the lid.

The practice of removing an icepack from the carrier and placing the reconstituted vial in the hole molded into its surface is no longer recommended. Placing freeze-sensitive vaccines in contact with a frozen icepack could result in loss of vaccine potency.

E004.4: Calculating requirements

To calculate the quantity of vaccine that must be transported, use data on vaccine volume per dose taken from Table 7 of the WHO guidelines on the international packaging and shipping of vaccines or use the EVM assessment tool which can be downloaded from the website of the Effective Vaccine Management Initiative.^.

E004.5: Future developments

There is an increasing need for larger-capacity products in the immunization supply chain because vaccine volumes are increasing dramatically. Large-capacity insulated containers would offer the possibility of simpler and more secure transport for large quantities of vaccines from primary to sub-national level. WHO will explore developing suitable PQS specifications for this type of insulated container.

CATEGORY DOCUMENTATION, GUIDANCE FOR MANUFACTURERS/SUPPLIERS & SUPPORTING INFORMATION FOR USERS

E004: Cold boxes and vaccine carriers

E004: Cold boxes and vaccine carriers

Performance specifications

Verification protocols

Guidance for manufacturers/suppliers

Supporting information for users