|Table of Contents|
Common Terms in Cold Chain
Insulated containers that can be lined with coolant packs to keep vaccines and diluents cold during transportation and/or short period storage. Cold boxes are used to collect and transport vaccine supplies from one fixed vaccine store to another, and from vaccine stores to health facilities. They are sometimes also used to temporarily store vaccines when the refrigerator is out of order or being defrosted.
Equipment and practices used to ensure a constant temperature for a product that is not thermostable (such as vaccines, serums, tests, etc.), from the time it is manufactured until the time it is used. It also includes all the temperature monitoring equipment and routines.
The number of hours the temperature inside a passive cold chain container stays below +8º C. This depends on the ambient temperature, the number of times the box is opened and for how long, the number and temperature of the ice packs used, but also on the quality of the box, how well it closes and insulates. Cold life tests are performed at +43º C. Do not confuse “Cold life” with “Cool life”.
The number of hours the temperature inside a passive cold chain container stays below +20º C.
Also referred as “ice packs”, are flat, square plastic bottles that are filled with water and cooled. They are used to keep vaccines cool inside the vaccine carrier or cold box.
The process of planned removal of equipment from an active status and its storage in a secure and safe place until disposal.
|Disposable Insulated Carton Box|
Passive cold chain portable container used by producers to ship their vaccines around the world. Generally, they consist of a polystyrene box inserted in a cardboard box for transport of large quantities of vaccines in
favourable circumstances (e.g. in an airplane). They have a limited cold life (often with a maximum of 4 days).
The process of national regulatory authority evaluation of an individual lot of a licensed vaccine before giving approval for its release on to the market.
A document summarizing all manufacturing steps and test results for a lot of vaccine, which is certified and signed by the responsible person of the manufacturing company. Also called “lot summary protocol”
Small cold boxes, portable by one single person, used to keep the vaccine cold for short transport, or to store vaccines temporary just before vaccine administration. There are many types.
|Expanded Programme on Immunization (EPI)|
Global program initiated by WHO with the objectives to ensure immunization of all children against certain diseases (such as measles, rubella and tetanus) and to eradicate poliomyelitis, and to extend all new vaccine and preventative health interventions to children in all districts in the world.
WHO audited and pre-qualified medical equipment based on Performance, Quality and Safety (PQS) requirements. The list of validated equipment is accessible online and used by several agencies as reference for procurement.
Vaccines that come as a liquid and are ready to use in the person.
The vaccines that come in a lyophilized (or freeze-dried) state and need to be reconstituted at the vaccination site. The latter come in two vials: one for the lyophilized vaccine, the other containing the diluent (saline solution).
|Solar Direct-Drive (SDD)|
Refrigeration technology for solar powered devices that avoids the batteries for energy storage.
|Vaccine Preparation||The process of mixing freeze-dried vaccine with the diluent. Consider that vaccine produced by one manufacturer must never be used with diluent produced by another.|
|Sensing/Monitoring Equipment||Specialized instruments that remotely monitor and log data on cold chain facilities, including ongoing inside/outside temperatures, and temperature events.|
Vaccines are made from micro-organisms similar to the ones that cause disease, or from the toxins that bacteria produce. Therefore, all vaccines are sensitive biological substances that progressively lose their potency (i.e. their ability to give protection against disease). This loss of potency is much faster when the vaccine is exposed to temperatures outside the recommended storage range.
Health workers and logisticians involved in vaccines management are responsible for maintaining the adequate storage and transport conditions: while vaccines are stored in the vaccine stores at the province and county levels, or while they are being transported to township and villages, and while they are being used during immunization immunisation sessions or rounds.
All relevant staff must be trained to both use and manage the cold chain equipment and to regularly monitor the temperature. This includes having appropriate and efficient logistics mechanisms to manage shipping, fuel, spare parts etc.
The main technologies used to produce cold are: compression, absorption, solar battery powered and solar direct-drive.
Also known as “Mains powered refrigerators”, these are the models most commonly used. They run solely on electricity. These models use little energy, require little maintenance, produce significant amounts of cold quickly and are easy to repair. They are equipped with a thermostat for setting the desired temperature.
Compression type refrigerators are loaded with a coolant fluid agent which in the form of gas is pumped by a compressor to the condenser where it forms as a liquid. This liquid later vaporizes vaporises in the evaporator, capturing heat and therefore cooling the surrounding air. The gas returns to the compressor to begin the cycle again, as long as the thermostat keeps the circuit closed and the compressor running.
There are four different types of compression refrigerators and freezers: (1) Refrigerator only, (2) Freezer only, (3) Refrigerator and Freezer (with different compartments), and (4) Refrigerator or Freezer (the entire unit is used either as a refrigerator or as a freezer).
These types of devices draw energy from kerosene or gas (butane or propane) normally combined with an alternative electrical connection. The coolant agent used in these devices is a solution of water, ammonia, hydrogen with a small quantity of anti-corrosion. The cooling circuit is closed; therefore, it is not possible to fill it with or repair it if there is a leak.
Because of all the above-mentioned reasons, some agencies no longer recommend the procurement of absorption type refrigerators, preferring solar powered systems. However, this type of devices is still used in some remote regions.
Solar Battery-Powered Models
Battery-powered solar refrigerators were introduced as an alternative to the absorption type refrigerators. They are a solution to the challenges of storing vaccines in locations without reliable electricity or with electricity problems.
However, experience gained over the time has shown that this technology is more expensive than absorption and grid-powered options. Furthermore, the degree of reliability of solar power decreases as lead-acid batteries require maintenance, are often used for other purposes and must be replaced about every three years. In addition, the batteries contain toxic materials that are difficult to dispose of safely.
Solar Direct-Drive Models
Solar direct-drive (SDD) models eliminate the dependency on the batteries used to power solar refrigerators. The energy is directly supplied by the solar panels: when sufficient light is captured, a DC compressor pushes the refrigerant through the cooling system to form ice in a compartment separate from the vaccine storage unit. This ice bank serves to store thermal energy rather than chemical energy, keeping the fridge cold even in the absence of sun.
There are two main type of devices - reusable containers (cold boxes and vaccine carriers) and disposable boxes.
Cold Boxes -
Insulated reusable containers that loaded with coolant packs are used to transport vaccine supplies between different vaccine stores or to health facilities. They are also used to temporarily store vaccines when the refrigerator is out of order or being defrosted.
The vaccine storage capacity of cold boxes ranges between 5 and 25
Litres and its cold life can vary from a minimum of 48 hours to a minimum of 96 hours (known respectively as “short range” and “long range” cold boxes).
|Vaccine Carriers -|
|Insulated reusable containers that, when lined with coolant packs, keep vaccines (and diluents) cold during transportation from health facilities with refrigeration to vaccination sites where refrigeration and ice are not available. They are smaller than cold boxes and therefore easier to carry by a single health worker travelling on foot or by other means, where the combined journey time and|
|immunisation activity ranges from a few hours to a whole day. The vaccine storage capacity of vaccine carriers are between 0.1 and 5.0|
|Disposable Insulated Boxes - (also known as Insulated shipping containers)|
|Insulated containers, manufactured in carton or|
|moulded foams such as polyurethane, polyethylene or expanded polystyrene (EPS). Some are designed for single use while others are returnable for reuse. They are used for the transport of vaccines over long distances. Normally used for products delivery from the central suppliers to main vaccine stores. Their storage capacity, temperature range, cold life and resistance vary among different solutions: some solutions are suitable for Road transport with hold on times between 36-48 hours while some other solutions are suitable for air transport with hold on times up to 120 hours. One main concern related to disposable insulated carton boxes is its single-use lifespan and its low-cost material composition of EPS and water-based gel packs, rarely recyclable.|
Cold Chain Storage for Vaccines
Quantity of Vaccines - will depend on the targeted population to be immunizedimmunised, the vaccine consumption and the vaccine supply frequency and reliability.
It is advised to add a safety margin in the storage capacity to respond to stock peaks that may overwhelm the cold chain storage capacity (see figure below, taken from WHO Guideline for establishing or improving primary and intermediate vaccine stores). Stock peaks occur when the volume of vaccine actually distributed in the period between any two supply intervals is less than the volume predicted to be distributed during this period. They can also arise if a vaccine delivery arrives earlier than anticipated. Overstocking and understocking under-stocking are also caused by seasonal fluctuations in demand, campaigns, National Immunization Immunisation Days and so forth.
In addition to stock peaks, it is recommended to maintain some extra store capacity as back-up to overcome equipment malfunctioning or maintenance (i.e., emptying a refrigerator for defrosting).
Type of Vaccine - of key importance because different vaccines have different presentations. The most common are vials (or ampoulesampules), but also, single-dose prefill pre-filled syringes may be stored. Depending on the vaccine, vials can contain different number of doses, normally 1, 10 or 20 doses. Because of these different presentations, the key variables used to calculate the required volume for vaccine storage are the number of doses to be stored and the estimated volume per dose. The estimated volume per dose (or packed vaccine volume) quantifies the space needed to store or transport vaccines and diluents and will depend on the number of doses per vial, the physical size of the vial or ampoule ampule (primary package) and the bulkiness of the external packaging (secondary packages).
|Multi-Dose Vaccine Vial||Single-Dose Pre-filled Vaccine Syringe|
It is important to consider that some presentations include the diluent in the same packaging as the vaccine. In such cases it is necessary to refrigerate the diluent as well as the vaccine. In all cases, diluents should be refrigerated 24h prior to vaccine preparation. Refrigeration of diluents is normally done in the last step of the vaccine supply chain.
Whenever possible, the packed vaccine volume per dose should be calculated using data from the vaccine manufacturer or supplier. The World Health Organization Organisation (WHO) and the United Nations Children’s Fund (UNICEF) online databases provide access to data on the packed vaccine volume per dose or the dimensions of vaccine and diluent packaging for WHO-prequalified pre-qualified vaccines.
To calculate required vaccine storage capacity, it is recommended to use the WHO guidance document for vaccine volume calculation: How to calculate vaccine volumes and cold chain capacity requirements.
Measuring the length, width and height of the vaccine packaging and dividing the resulting volume by the total number of vaccine doses contained in that packaging, may be an alternative method for vaccine volume calculation.
Cold chain encompasses the infrastructure, the equipment, the people and the management processes and its implementation. The following criteria (adapted from WHO Effective Vaccine Store Management initiative) are universal conditions that can be used during any cold chain assessment.
Assessing the Management Processes
Assess the availability of a cold chain management policy or standard operating procedures. It should be available and applied. Cold chain management policy or standard operating procedures should include clear information on:
- Designated staff members responsible for the cold chain management, including the decision makers accountable for ensuring the required resources.
- Vaccine stock requirements specific to the workplace, both in terms of volume and temperature ranges.
- The “safety stock level” and the “maximum stock level” for each vaccine. Stock levels should be maintained between this range.
- Vaccine ordering and stock management processes, including:
- Stock records.
- Process to order, receive and dispatch vaccines, including the equipment required in all deliveries, such as Freeze indicators.
- Standardized Standardised recording and reporting of all stock transactions.
- Process for managing damaged vaccines and respective process for quarantine, disposal or reverse logistics.
- general warehousing practices like periodic physical inventories.
- Temperature monitoring process: required equipment, templates, schedule and reporting processes.
- Operation and maintenance plan, including a specific schedule for all the cold chain equipment. It should include a designated person or service provider responsible for the servicing of the power sources and cooling equipment.
- Actions if the temperature recordings are outside the +2°C to +8°C range.
- Emergency plans and equipment for use in the event of refrigerator failure and/or power outage, including a nominated back –up provider.
- The processes to ensure sufficient funds to cover the required equipment and consumables. A replacement plan for cold chain equipment reaching the end of its lifespan should be considered.
Assessing Cold Chain Equipment
The assessment of the cold chain equipment should include both active and passive cold chain devices as well as other cold chain material such as coolant packs and temperature monitoring equipment. For the existing cold chain equipment, assess:
The age and past handling of the equipment could be a vulnerability factor: assess its first “use date” and past history. Be aware that refrigerators have a life duration of about 10 years.
The infrastructure should enable the cold store to function effectively. This includes the adequateness of the store building (the location and the construction standard) and the basic utilities, particularly the power supply feeding the active cold chain.
All the infrastructure should be of a satisfactory standard and correctly maintained through planned preventive maintenance. Emergency repairs should be exceptional and conducted in a timely manner. There should exist reports on maintenance and repairs. Adequate supplies of spare parts, consumables and fuel should be available. If relying in an emergency generator, it should be also well serviced and operational.
Assessing Human Resources
The assessment of the human resources involved in the cold chain management should include (1) the responsibilities, (2) the correct staffing and (3) the knowledge and capacities.
There should be enough Human resources to operate the store effectively. Even in the smaller vaccine store sites, two or more staff should be appointed to ensure the coverage during unexpected events. A workplan work-plan should guarantee the coverage throughout the whole year.
Solar devices are suitable for those facilities with sufficient solar energy available at installation locations: basically, strong enough sunlight all year round and clear surroundings without buildings or trees. Be aware that mountainous areas and coastal regions may have microclimates micro-climates with prolonged cloud cover. In these cases, the choice of solar technology will be limited and its implementation will require careful design to ensure adequate performance. In addition, it is advised to have a solar service provider able to deliver all necessary services, including site assessments, equipment installation, training, corrective maintenance, and repair.
The following figure, taken from WHO, Introducing Solar-Powered Vaccine Refrigerator And Freezer Systems, A Guide For Managers In National Immunization ProgrammesImmunisation Programmes, provides a decision tree to guide in the selection of the most appropriate energy source for vaccine refrigeration:
Refrigerators and freezers are available in several shapes and sizes. Top-opening refrigerators and freezers, although are the first choice for bulk vaccine storage, occupy more floor space per liter litre of vaccine than front-opening models. Front-opening refrigerators or refrigerator/freezer combinations are easier to accommodate in reduced spaces and offer an easier access to vaccine.
It is important to take into account, as part of the environment criteria, the ambient operating temperature range where the refrigerator or freezer performs. This information should be provided by the manufacturer. Though a standard is a range between +5°C and +43°C, some models have a maximum ambient operating temperature of +32°C.
Support and Standardizationand Standardisation
As a general rule, when possible and if reviews show that the cold chain is well managed and that temperature monitoring procedures are reliable, select cold chain equipment similar in technology to the one already in place. This has obvious operational advantages.
Capital costs are one-time costs incurred at the time of purchase. It includes: the costs of the equipment, recommended spare parts, in-country transport, installation kit, and installation laborlabour.
Operating expenses are the recurring costs over the useful life of the equipment. This includes cost of energy (electricity, gas, kerosene), maintenance, repairs and decommissioning plus the costs of operation and training of staff.
- Holdover time for ILRs based on a facility’s power reliability.
- Autonomy time for SDD devices based on regional climate factors.
- Freezer capacity for ice pack production.
- Ease of use, including:
- Readability of control panels and displays by a standing health worker
- Use of internal storage racks, boxes or drawers to help organize organise vaccines and separate other medicines that are stored in the device.
- Voltage stabilizer stabiliser integration.
To evaluate the cold chain equipment options from a cost perspective, it is advised to use the “PATH Total Cost of Ownership tool”. The tool allows users to explore the capital and operating costs associated across various cold chain equipment technology categories, as well as to compare costs for specific models within a technology category or across multiple technologies.
Installation, Loading and Maintenance
Installation of cold chain equipment must be done in the adequate room. The room must be accessible for vaccine reception and delivery, large enough, in good building conditions (roof, ceilings, floors, electrical services, etc.) and secure. Useful information can be found in WHO’s Guideline for establishing or improving primary and intermediate vaccine stores and WHO-UNICEF’s Effective Vaccine Store Management Initiative.
- Place it out of the sun, away from any source of heat (stove, radiator) and protected from dust.
- The room must be at least 20 m3 of volume, be well aerated and cool if possible; always respect the ambient operating temperature range indicated by the manufacturer.
- Make sure there is clearance between the unit and a wall, partition or other equipment in order to allow air to circulate and facilitate maintenance; the clearance distance should be of at least 25 cm for compression type refrigerators and 40 cm for absorption type refrigerators.
- The refrigerator/freezer should be placed on blocks or pallets to avoid direct contact with the ground, protect against humidity and increase heat evacuation.
- Install it horizontally to ensure good circulation of the cooling fluid.
For equipment powered by electricity, it is essential that it is installed according to the national standards of electrical equipment installation. Devices not having an integrated voltage stabilizerstabiliser, must be protected relying on standalone voltage stabilizerstabiliser. This is critical wherever voltage fluctuations exceed ±15% of rated voltage (or the refrigeration equipment manufacturer’s voltage tolerance, whichever is lower).
- Cool-down time: Start the refrigeration unit when the room is empty and the same temperature exists inside and outside the room. Keep the cold room door closed during the test. Record the time needed for the internal temperature to drop below +8°C. Run the test for at least 48 hours.
- Running test: Record the number of hours that the compressor runs with the door closed and the room empty. Monitor the internal and external temperatures, the evaporator and condenser temperatures, and the pressures of the system. Measure the maximum temperature difference in the cold room and record the locations of any warm and cold spots.
- Temperature-rise test: Cut off the electricity supply to the room and measure the period required for the internal temperature to rise to 5°C above the normal operating temperature.
- Control and monitoring equipment tests: Test the operation of the automatic duty-sharing, temperature control and temperature-monitoring and alarm equipment. If computerized computerised temperature monitoring is used, load, configure and test the software.
- Stand-by generator operation test: Check the power output of the stand-by generator and the operation of the automatic mains failure control system. Run the generator continuously for 48 hours under load.
For detailed installation instructions for refrigerators and freezers, check EVM Model Standard Operating Procedures, Consolidated version, with user guide, from the Effective Vaccine Management Initiative.
Basic recommendations for loading the refrigerator units with vaccines, include:
- Do not store unauthorized unauthorised products (like food or drinks) in refrigerators used for thermo-sensitive products storage. Overload and continuous opening reduce the performance of the equipment and affect negatively temperature stability.
- Keep all vaccine stacked on shelves or baskets, not on the floor.
- Do not append the boxes together or in contact with the walls: leave a space between them to allow cold air to circulate.
- Be careful, not to store freeze-sensitive products in the coldest part of the fridge (in contact with the evaporator): in the bottom for horizontal/top door fridge and on the top for vertical/front door fridges.
- Do not store any vaccine in the doors of vertical/front open refrigerators.
- Keep all vaccines in its inner cardboard box. There should be no loose vials in the store.
- Products should be quickly identifiable in order to reduce the time with the door open. Names and expiry dates must be located on the front and be readable as soon you open the fridge.
- Store the vaccine systematically and keep together the contents of each batch.
- To facilitate handling and reduce the time opening the door, apply a positioning rule. For example, the rule: expiration date closest to the left of the shelf and the farthest to the right. Products with expiry dates closest leave first, then date more distant.
- If there is enough place, the diluents may be stored in the refrigerator also. Remember that vaccine produced by one manufacturer must never be used with diluent produced by another.
- Each refrigerator must be equipped with a thermometer and other mandatory indicators.
For further details on arrangement of vaccines with specific rules for using front or top-opening refrigerators, read WHO’s Immunization in WHO’s Immunisation in Practice: A practical guide for health staff.
Cold chain equipment needs periodic maintenance and repairs. Maintenance should be planned from the moment of installation by defining a regular schedule of basic tasks to be implemented by on-site workers.
- Temperature control and monitoring: This will allow the review of the system performance. Check and record the temperature twice a day. A convenient routine is to do so, first thing in the morning when opening the facility, and last thing in the evening before closing it. Analyse the trend of recorded temperatures and report and investigate any abnormality.
- Visual inspection inside: Weekly check if excessive ice has accumulated in the interior and the evaporator plate. Ice reduces device performance, requiring more electricity, gas, kerosene or solar power. Whenever the ice on the inside lining is thicker than 5mm or at least once per month, defrost the unit and clean and dry the interior of the refrigerator and/or freezer. Regularly check for signs of damage, including corrosion and deformation of the door or lid seal. Carry out repairs as necessary. A door not closing properly or being open too often are the main causes of excessive formation of ice.
- Visual inspection outside: monthly clean and wipe the dust accumulating on the back of the refrigerator and/or freezer (condenser and cooling unit). Excessive dust may reduce device performance. Do not allow rubbish and packaging to accumulate in the vaccine storage area. It is essential to maintain free air movement around the condensing units. Regularly check for signs of rust and carry out repairs as necessary.
- Visual inspection of the source of energy: Maintain the source of energy (mains, voltage stabilizerstabiliser, batteries, solar panel, etc.) according to the instructions of the manufacturer.
Be aware that some types of temperature monitoring equipment are battery powered. These devices contain a non-replaceable battery with a minimum operating life of 2 years from the date of activation. It is essential to include the replacement of these devices as part of their routine preventive maintenance programme.
Decommissioning and Disposal
Decommissioning and disposal are the last stages in the life cycle of the cold chain equipment. When the equipment become technically obsolete or repair and maintenance costs become higher than the remaining value of the equipment, decommissioning and disposal should be considered.
There are several disposal methods depending on the degree of obsolescence of the cold chain equipment: unrepairableun-repairable, ineffective for vaccines, costly, surplus due to downscaling down-scaling of operations, etc. The most common methods for disposal are: donation, transfer, sale, recycling (spare part harvesting) or destroyed.
- Calculating the volume of vaccine to be shipped.
- Evaluating the journey circumstances.
To calculate the volume of vaccine to be shipped, it is necessary to know for each vaccine and diluent in the shipment:
The maximum recommended packed volume per vaccine dose and diluents are:
Dose per vial
cm3 per dose
DTP, DT, Td, TT
DTP-HepB+Hib (freeze dried)
1 in UNIJECT
TT in UNIJECT
Diluent for BCG
Diluent for Hib
Diluent for measles, MR, MMR
Diluent for meningitis A&C
Diluent for yellow fever
17.0 (per unit)
Diluent for BCG
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:
There are several alternatives for the shipment of temperature-sensitive cargo:
Refrigerated (Multimodal) Containers
A refrigerated (multimodal) container or reefer, is a shipping container equipped with an integrated refrigeration unit for the transportation of temperature-sensitive cargo. They rely on external electrical power provided from the ship, the quay or the trailer. This These type of containers is are suitable for large-scale shipments and when the journey requires changing modes of transport (i.e. road-sea-road). Normally , normally over long distances.
This type of shipment is Refrigerated containers are rarely used for vaccine transport. For long distances or inter-continental movements, vaccines are commonly air-shipped in cold storage containers, which are either actively powered or passively kept cold. Therefore, refrigerated multimodal containers are not advised for transportation of vaccines.
A refrigerated vehicle is a van or truck with a thermally isolated cargo compartment, equipped with a mechanical refrigeration system for road freight transport at specific temperatures.
Such vehicles are utilized utilised for large-scale transport of vaccines from the manufacturer to primary/central stores and in certain context for bulk transport between primary/central stores and secondary stores. Refrigerated vehicles are commonly run by specialized specialised logistics operators. Please review the checklist for contracting refrigerated vehicles in the road transport section of this guide.
Still, the high cost of refrigerated vehicles and their tendency to suffer mechanical breakdowns, have prevented many developing countries from using this transport method for regular deliveries. Additionally, when using a refrigerated vehicle in such contexts, it is recommended cold packing provisions to protect vaccines in case of vehicle breakdown.
Given that some cold boxes, if properly loaded, have enough cold life to cover transportation needs at national level, the use of refrigerated vehicles for bulk transport of vaccines is also discouraged if reliable infrastructure is not accessible.
Portable Passive Vaccine Containers
A portable passive vaccine container is a container that maintains a temperature-controlled environment inside an insulated enclosure, generally without thermostatic regulation, using frozen ice-packs, conditioned ice-packs, cool water-packs or warm water-packs. In this guidance, it includes reusable insulated cold boxes and vaccine carriers as well as single-use insulated cartons. Because of the different models available, its versatility and its cost, they are the most used containers for the transport of vaccines.
Reusable containers generally used to transport vaccines from one fixed vaccine store to another, and from vaccine stores to health facilities. They have a vaccine storage capacity between 5.0 and 25.0 litres. There are two types of cold boxes:
|Vaccine Carriers||Used for transporting vaccines where the combined journey time and immunization immunisation activity ranges from a few hours to a whole day. The vaccine storage capacity of vaccine carriers is between 0.1 and 5.0 litres.|
- The heat and freeze sensitivity of every vaccine being transported. If available, refer to manufacturer indications for further information on temperature sensitivity of vaccines. In any other case refer to WHO How to use passive containers and coolant-packs (Annex 1).
- The required cold life to keep vaccines at safe temperatures for an entire transport or outreach session. For vaccination outreach sessions the considered time should include travel to and from the vaccination site, allowing the safe management of non-used vaccines.
- The required capacity based on the volume of vaccines to be transported.
When selecting the appropriate container, the time of transport must be considerably less than the cold life of the container. Unexpected events such as vehicle breakdowns, human error or carelessness, often delay the time of transport. When the duration of the journey exceeds the cold life of the container, it is possible to replace the coolant packs if necessary. The back-up coolant packs can be transported in a separated container or swapped in a stop-by storage facility with compatible coolant packs. It is therefore necessary not to compromise on the number of ice packs which may need to be prepared.
Once the decision about the type of container is taken, calculate the number of cold boxes required. Subsequently calculate the number of coolant packs and temperature tracking and alert devices required. Each container holds a specific number of coolant packs.
|Water-Filled Coolant Packs||The most commonly used, they are available in a solid rectangular plastic container in different sizes. The most common are: 0.3 litres (in two different sizes: 173x120x26mm and 163x90x34mm), 0.4 litres (163x94x34mm) and 0.6 litres (190x120x34mm). They are used to maintain temperatures in reusable cold boxes or vaccine carriers. WHO currently recommends the use of water-filled coolant packs. Drinking water is safe for such use and is generally available; this makes it the most practical substance for filling coolant packs because both water and ice can effectively control the temperature of the vaccine load, when correctly used.|
|Gel-Packs||sealed coolant containers prefilled pre-filled with a mixture of water and additives. They are available in flexible plastic bag or in a rectangular plastic container. WHO does not recommend using gel-packs because their thermal properties (freezing point of some gel-packs can be significantly below 0°C) and their lower durability.|
|Phase-Change Material Packs (PCM-packs)||containers filled with other phase-change materials different from water. They can be designed to change phase at the convenient temperatures range, overcoming the vaccine freezing risk associated with frozen water. However, they are also more expensive and their conditioning process is longer and more complex.|
Vaccine manufacturers ship products by air using coolant-packs of various types and sizes containing various fill materials, including water, gel and PCM. It is a common practice to reuse these coolant packs recovered from international shipping containers. WHO discourages this practice as these packs do not necessarily perform in the same way as the water-packs. In addition, they are not designed for repeated use and may not be dimensionally compatible with most of the passive containers used for the in-country supply chain. The recommendation is that, after vaccine arrival, these packs are removed from the receiving vaccine store and recycled or disposed of according to the vaccine manufacturer’s recommendations and/or national waste management policies. 
The temperature of coolant packs must be set according to the temperatures required by the vaccines to be shipped. There are two main possibilities: (1) the vaccines to be shipped in the cold box may be frozen (Measles, Polio, Yellow fever, Meningitis, etceteraetc.); (2) the vaccines to be shipped in the cold box will be irreversibly damaged when frozen (DTP, DT, Td, TT, Hep A and Hep B, Hib).
For international/air shipments, a label must be affixed to the front surface of each package indicating type of vaccine, name of manufacturer, presentation, batch number, date of manufacture, date of expiry, quantity, and storage conditions. The manufacture date and expiry date on all labels should be written in full, not in a coded form (i.e. June 2017, not 06.17). In addition, required temperature conditions for transportation must be clearly visible on the outer carton, indicating clearly where recommended transportation temperatures differ from recommended storage temperatures.
A “Vaccine Rush” Label must be affixed to each face of the vaccine package
A “Do Not Freeze” label must be affixed to those packages (in each face) containing freeze-sensitive vaccines, droppers or diluents.
An IATA Time and Temperature Sensitive Label (mandatory from 2012). The lower half of the label must never be left blank and must indicate the external transportation temperature range of the shipment - this can be hand written or printed onto the label.
Labels must be written in a language appropriate to the country of destination.
A list of contact points for national regulatory authorities in countries producing vaccines prequalified pre-qualified for purchase by United Nations agencies can be found in the Annex 3 of WHO Guidelines on the international packaging and shipping of vaccines.
If using a third-party logistics provider, make sure that they are prequalified and approved for freight forwarding/transport.
If organizing organising the shipment by own means, ensure that the designated vehicle is in good working condition and that the driver is aware of the cargo sensitiveness. Provide the driver with clear instructions and the necessary means to ensure proper load, handling and transport. This should include:
- Always placing the cold box in the vehicle in shadow and away from warm spots, avoiding the trunk of the vehicle as this is not a refrigerated space within the vehicle.
- The cold box should be secured firmly.
- Use of shaded and secure parking areas, minimizing minimising the time during which the vehicle is unattended.
- Avoid opening the cold chain containers during transit.
- Emergency contact information to call in case of breakdown or unexpected events.
The arrival of a vaccine shipment in a country, and its subsequent clearance through customs and transportation to the central vaccine store are the most critical stages in the shipping process. These are frequently the times when mistakes and delays occur, resulting in damage to the vaccines.
Reception at Customs
Regarding the customs clearance of the vaccines, the same procedures as described in the Customs topic apply, but with additional specific requirements linked to vaccine management. Note that requirements vary from country to country.
- National regulatory authorities (NRA) or head of customs in the destination country. To be cleared, the vaccines must have received marketing authorization authorisation and a release certificate from the national regulatory authority.
- Local Ministry of Health (MOH): depending on country specific requirements, the MOH may issue a letter approving the shipment.
Importing vaccines through ports that don’t have the adequate cold storage facility is not recommended. In the event of receiving a shipment of vaccines needing clearance in a port without cold storage facility or if the cold room is inaccessible, arrangements should be done for immediate release of the vaccine shipment. Coordination with the relevant authorities for an agile clearance and/or for safe and appropriate management and storage of vaccines at the airport are therefore needed.
Reception at the Storage Facility
Previous to reception make sure that a copy of the freight documents is available. Refer to the information about “Documentation” above.
Ensure priority unloading. Remove product from the vehicle and check that the number of boxes matches the number of boxes shown in the packing list. If it does not, note it conveniently in the provided way billwaybill. Also indicate in the way bill waybill if the shipping boxes were received in good condition and if all necessary labels on the outside of the shipping boxes were present.
Specific considerations must be taken regarding transport of vaccines and coolant packs when organizing organising mass vaccination campaigns. In such events, numerous teams deploy simultaneously to different vaccination points carrying their own passive cold chain means. The number and rotation of coolant packs and the freezing capacity of the active cold chain must be carefully planned as the ice-pack turnover will be very high, and the period for their reconditioning can last more than 24 hours.
The performance of a vaccination team depends on the flow of people through the vaccination site, the number of working hours, and the number of vaccinators and vaccine preparers in each team. Though this will depend enormously on the environment (rural/urban), the organization organisation of the vaccination site, and the number of vaccine preparers per vaccinator, with a steady flow of people, one vaccinator can vaccinate on average 1 to 3 people per minute.
The figure below shows an example of the stock management of ice during a 15 days mass vaccination campaign with a total freezing capacity is 250 kg per 24 hours.
<center><table width=650px> <tr><td> <center><font size=5> Estimated Stock Management (KG of Ice / Day) </font></center> </td></tr> <tr><td> <center> <img src="https://dlca.logcluster.org/download/attachments/9405290/SMG1.png" width=600px> </center> </td></tr> <tr><td> <center><img src="https://dlca.logcluster.org/download/attachments/9405290/SMG3.png"> Stock <img src="https://dlca.logcluster.org/download/attachments/9405290/SMG4.png"> Out <img src="https://dlca.logcluster.org/download/attachments/9405290/SMG5.png"> In <img src="https://dlca.logcluster.org/download/attachments/9405290/SMG6.png"> Balance</center> </td> </tr> </table> </center>
A cold chain with regular vaccine shipments to storage facilities/health centres, implies that a significant amount of material gathers at the end of the supply chain. This material is often single use (isothermal boxes and gel coolant packs) or with a short lifespan (temperature monitors).
A solution to deal with such materials should be duly defined and implemented within the organizationorganisation, avoiding bad practices such as uncontrolled disposal or gathering of useless material in inappropriate locations (such as health centres). This can entail transporting such material back to a location where it can be duly disposed or recovered.
Temperature monitoring devices and routines are used during every storage and during every transportation stage, until the vaccine is administered to the recipient. Depending on the supply chain level (central store, intermediary store or outreach and transportation container) different monitoring devices are used.
Devices for Cold Rooms and Freezer Rooms
For Cold Rooms and Freezer Rooms, monitoring devices integrate different functions like temperature and event loggers and alarm systems. They are fed by several sensors allowing the temperature monitoring in several room locations simultaneously. These systems are commonly configurable to suit user requirements by adjusting parameters such as logging interval or measurement unit.
Devices for Refrigerators and Freezers
The temperature in refrigerators and freezers is commonly monitored by the use of (analogicanalog) thermometers and (digital) data loggers. Data loggers are battery operated devices which measure and store data for a period of time. The time limit is the device memory. Some data logger models display the data instantly on an LCD screen while some other require data to be downloaded by USB or cable to a computer for later analysis.
- Threshold type.
- Progressive type.
Threshold Type chemical indicators provide a signal only when exposed to temperatures higher than (ascending indicator) or lower than (descending indicator) a predetermined threshold temperature. They are irreversible (thus, single-use) and are suitable for high or low temperatures.
Example of these devices are:
|TempTime LIMITmarker™||Temptime FREEZEmarker®|
Type chemical indicators register multiple events in a cumulative way. Whenever the threshold temperature is exceeded the reaction is activated and the indicator starts to change. Further temperature violations increase the change process. The indicator for this type of device usually takes the form of a progressive
colour change along a paper strip.
Cold Chain Monitor (CCM) Card
Paper-based temperature monitoring device which change
colour irreversibly and at a constant rate. Indicator strips are attached to a card on which instructions for use are printed.
CCMs provide a warning when excessive heat exposure occurs during transport. They are used primarily to monitor the international shipment of freeze-dried vaccine consignments where dry ice is used. CCMs may also be appropriate for national vaccine shipments where the delivery takes several days.
Vaccine Vial Monitor (VVM):
Heat-sensitive label that gradually and irreversibly changes
colour as the vaccine is exposed to heat. It warns the health worker when a vial should be discarded because the vaccine is likely to have been degraded by exposure to heat. For instructions on how to interpret VVM, refer to WHO How to Monitor Temperatures in the Vaccine Supply Chain
Electronic Freeze Indicators  - used to check if vaccines are exposed to freezing temperatures during storage or transport. The alarm indicator is triggered and displayed (changing from a “√” to an “X”) if exposed to temperatures lower than -0.5 °C for a continuous period of 60 minutes. To avoid malicious manipulation, once the alert is triggered, the alert is irreversible. If this happens the device is no longer usable and should be discarded. Otherwise, the device can be used until the built-in battery expires. The intermittent “dot” icon confirms active monitoring.
Electronic Shipping Indicators - more sophisticated devices that show if a product has been exposed to temperatures beyond the assigned alarm settings. They record the temperature at regular intervals during a certain period (normally not exceeding 20 days due to memory overflow). They have a digital display that reflects if the vaccine being shipped crossed the alarm thresholds.
Shipping indicators are mounted on a colored coloured card (yellow or blue) with a data entry section on one side, which the manufacturer fills in at the point of dispatch, and an instruction and interpretation section on the reverse side for the recipient. Yellow indicators are for freeze-sensitive vaccines, and blue indicators are for heat-sensitive vaccines.
Temperature-monitoring and record-keeping are required to make sure that each vial of vaccine is maintained under appropriate conditions. The data gathered from temperature monitoring devices must be recorded and analyzed analysed on a regular basis to demonstrate that vaccines are being stored and transported at the correct temperatures.
- Identify the affected products, mark them and place them in quarantine to avoid its use temporarily. A quarantine area should be clearly marked for this purpose in one functioning cold chain equipment.
- Write a cold chain breakdown report and send it to the relevant persons. It must be submitted as soon as possible. The report should include information about the products (name, manufacturer, batch number, expire date, quantity) and the details of the Cold chain rupture (temperature range, exposure time, source of the alert).
- Wait for pharmacist recommendations. Even if some cold chain break occurred, the vaccine could be used under certain instructions. In case that the vaccine must be discarded, proceed according to the national regulation.be discarded, proceed according to the national regulation.
Templates and Tools
Sites and Resources
- https://www.technet-21.org/en/ : global network of immunization professionals committed to strengthening immunization services by building relationships, sharing knowledge, coordinating activities, and aligning priorities and goals.
- UNICEF Cold Chain Technical Support
- WHO Performance, Quality and Safety (PQS)
- WHO Immunization Training Resources
- How to calculate vaccine volumes and cold chain capacity requirements, 2017, WHO/IVB
- Procurement Guidelines, Compression System Refrigerators and Freezers, 2014, UNICEF
- Procurement Guidelines, Solar Direct Drive Refrigerators and Freezers, 2014, UNICEF
- Procurement Guidelines, Vaccine Carriers and Cold Boxes, 2016, UNICEF
- Introducing Solar-Powered Vaccine Refrigerator And Freezer Systems, A Guide For Managers In National Immunization Programmes, 2015, WHO
- Guideline for establishing or improving primary and intermediate vaccine stores, 2002, WHO/V&B
- Effective Vaccine Store Management Initiative, 2005, WHO-UNICEF
- Immunization in practice: A practical guide for health staff. Geneva
User’s handbook for vaccine cold rooms and freezer rooms, 2002, WHO
Sites and Resources
- https://www.technet-21.org/en/ : global network of immunization professionals committed to strengthening immunization services by building relationships, sharing knowledge, coordinating activities, and aligning priorities and goals.
- https://www.unicef.org/supply/cold-chain-technical-support : technical guidelines on cold chain equipment and services.
- https://apps.who.int/immunization_standards/vaccine_quality/pqs_catalogue/index.aspx: WHO Performance, Quality and Safety (PQS), relevant documents, procedures, and data sheets for all currently prequalified products in the following equipment categories.
- https://www.who.int/immunization/documents/en/: Resource materials related to Immunization, Vaccines and Biologicals
- https://www.who.int/immunization/documents/training/en/: Immunization training resources
- Study protocol for temperature monitoring in the vaccine cold chain, 2011, WHO-IVB
- How to use passive containers and coolant-packs, 2015, WHO-IVB
- Guidelines on the international packaging and shipping of vaccines, 2019, WHO
- Technical Report Series, No. 992, Annex 5, Supplement 12, Temperature-controlled transport operations by road and by air, 2015, WHO
- User’s handbook for vaccine cold rooms and freezer rooms, 2002, WHO
- Decommissioning and Safe Disposal of Cold Chain Equipment, 2018, UNICEF-WHO
- Total Cost of Ownership Tool for Cold Chain Equipment, 2019, PATH
 Procurement Guidelines, Vaccine Carriers and Cold Boxes, 2016, UNICEF