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WHO-UNICEF. Ten Global Criteria for Effective Vaccine Store Management

 Rediger
  Published: 30.04.04 Updated: 30.07.2004 12:00:55

Ten key criteria for effective vaccine store management were agreed at a meeting of experts, which took place at WHO Geneva on 17th to 18th December 2001. These criteria form the policy foundation for the effective vaccine store management initiative.

The detailed implementation of the tools, guidelines and standards, which WHO/UNICEF will provide, will inevitably be subject to variation to suit national circumstances. Indeed, it will be a requirement of the process that countries have developed the model standards into a Quality Plan which suits local circumstances. However the ten key criteria are intended to have global applicability. They specify an agreed international standard of performance which all participating countries should aim to meet.

The following paragraph headings set out the criteria and briefly describe the reasoning behind each one. The self-assessment process is to be carried out over a twelve month period. If a storage facility already has access to comprehensive and reliable data, the self-assessment could be carried out retrospectively. Typically, however, the self-assessment process will begin once a programme has developed a country-specific Quality Plan, and the store has implemented the changes necessary to comply with the equipment and management standards set out in the plan. Satisfactory performance is set as the vaccine store meeting at least 80% of the each criterion.

The ten criteria are listed below.

1. Over a period of 12 months, pre-shipment and arrival procedures have ensured that all shipments were in satisfactory condition when received in the primary stores.

The arrival of vaccines in country, their temporary storage and clearance through customs and their subsequent transport to the central vaccine store is often the most critical stage in the cold chain. Unfortunately, experience shows that this is often the time when mistakes are made and delays occur. Such mistakes and delays may result in damage to the vaccine shipment.

The smooth arrival and handling of vaccine shipments depends on the manner in which each stage in the delivery process is performed. Many parties may be involved - for example the vaccine manufacturer, UNICEF Supply Division, the forwarding agent, the airline, the UNICEF field office, custom authorities, clearing agents and the Ministry of Health. Given the need to communicate accurate, time-sensitive information, and to act on this promptly, it is essential that strict guidelines are put in place to define the tasks involved, to assign responsibility for carrying out each task, and to monitor performance.

2. Over a period of 12 months, all vaccines have been stored within WHO recommended temperature ranges.

All vaccines are sensitive biological substances. Over a period of time, they lose their potency - that is, their ability to give protection against disease. The higher the temperature to which the vaccine is exposed, the quicker is the loss of potency. Some vaccines are also sensitive to freezing, and this can cause irreversible damage.

In order to maintain their quality, all vaccines must be continuously stored at the appropriate temperature from the time they are manufactured until the moment when they are used. Once vaccine potency is lost, it cannot be regained or restored, and without proper care, any vaccine will eventually become ineffective. Once this occurs, the vaccine will no longer provide any protection against the target disease and the product is then useless. In some cases, loss of vaccine potency may also cause the vaccine to become more reactogenic.

The only way that it is possible to prove that vaccines have been stored at the correct temperature at all times is by using a continuous temperature recording device. This instrument should be regularly calibrated to ensure that it is accurate. Temperature records must be inspected regularly and retained for auditing purposes.

The recommended conditions for storing EPI vaccines are shown in the figure below. This diagram indicates the recommended storage temperatures and the maximum storage times at each level in the cold chain. At the higher levels of the cold chain, i.e., at primary, and regional intermediate stores OPV must be kept frozen between -15oC and -25oC). WHO no longer recommends that freeze-dried vaccines (measles, yellow fever, Hib and BCG) be shipped and stored at -20°C. Storing them at -20°C is not harmful but is unnecessary. Instead, these vaccines should be stored and transported at +2°C to +8°C. All other EPI vaccines should be stored at between +2oC and +8oC at all levels of the cold chain.

Diluents for vaccines are not sensitive to storage temperatures as the vaccines with which they are used. They are normally stored at ambient temperature, unless the diluent is packed with the vaccine. In this case they should be kept in the cold chain at between +2°C to +8°C . Diluent vials must never be frozen.

WHO recommended vaccine storage conditions

 

Primary

Intermediate

Health Centre

Health Post

Region

District

OPV

-15oC to -25oC

+2oC to +8oC

BCG

WHO no longer recommends that freeze-dried vaccines be stored at -20°C. Storing them at -20°C is not harmful but it is unnecessary. Instead, these vaccines should be kept in refrigeration and transported at +2° to +8°C.

Measles

MMR

MR

Yellow Fever

Hib freeze-dried

HepB

 

DTP-HepB

DTP-Hib

Hib liquid

DTP

DT

TT

Td

Diluent vials must NEVER be frozen. When the manufacturer supplies a freeze-dried vaccine packed together with its diluent, ALWAYS store the product at between +2oC and +8oC. Where space permits, diluents supplied separately from the vaccine may safely be stored in the cold chain at between +2oC to +8oC.

3. Over a period of 12 months, the capacity of cold storage has been sufficient to meet the demand.

At all stores, but particularly at the primary level, new orders for vaccine must be placed early enough to ensure that a new shipment arrives before the safety stock level is reached. Supply intervals, working stock levels and safety stock levels should be selected to suit local circumstances, including available storage capacity and suppliers' lead times. Stores generally have longer supply intervals and larger safety stock levels the higher they are in the supply chain. For example, safety stock levels at the primary store are may be set at three month's normal consumption, whereas a health facility may only carry a two week safety stock.

When calculating the capacity of cold storage, programme managers must consider and balance a number of factors. These include financial considerations, vaccine expiry dates, supplementary immunization activities (NIDs and campaigns), seasonal access, seasonal demand, and cold chain reliability.

Storage capacity should be enough to accommodate peak level stock requirements for the routine immunization schedule. In addition, satisfactory arrangements need to be made to ensure that vaccine supplied for NIDs and campaigns can be temporarily accommodated in storage facilities that meet WHO standards.

4. Over a period of 12 months, the buildings, equipment and transport available to the programme have enabled the cold store to function effectively.

Vaccine stores should be housed in permanent buildings. These should be designed and constructed to a good standard to suit local climatic conditions. The building should have adequate spaces to accommodate the cold storage equipment; a store keeper's office; a temperature controlled packing area; space for storing diluent, packaging materials and cold boxes, and space for freezing and storing icepacks. The store should have good access for vehicles and adequate telecommunications.

Wherever possible, refrigerators and freezers should be chosen from the WHO/UNICEF Product Information Sheets. Similarly, wherever possible, cold rooms and freezer rooms should comply with current WHO specifications. Adequate arrangements should be made to ensure continuous temperature monitoring and to ensure continuous refrigeration in the event of refrigeration equipment failure. Vaccine stores should have a reliable electricity supply, with an automatic standby power supply in the event of mains failure.

Reliable and suitable transport is essential for the delivery of vaccines and immunization supplies. Without access to an effective and reliable transport system, the operation of the cold store cannot be regarded as satisfactory.

5. Over a period of 12 months, all buildings, equipment and transport have been correctly maintained.

In order to prevent breakdowns affecting the performance of the immunization programme, all equipment, transport and buildings should be routinely maintained to a high standard using a programme of planned preventive maintenance. Emergency repairs should become the exception rather than the rule and there should be zero tolerance of breakdowns affecting key equipment.

In all cases there must be a reporting system which records breakdowns and the use and replacement of spare parts and which monitors the effectiveness of repair procedures.

6. Over a period of 12 months, stock management has been effective.

In order to maintain the quality of vaccines throughout the cold chain, it is essential to keep complete and accurate records of all stock transactions.

  • A stock control system comprises three steps, each of which must be performed regularly, accurately and completely. The three steps are:
  • Checking and recording details of vaccine consignments when they arrive at a storage point;
  • Checking details and conditions of vaccine stocks during the time they are kept in storage;
  • Checking and recording details of vaccines consignments when they leave the storage point for distribution to regions, provinces, districts and eventually, the user.

In addition, good warehousing practices should be adopted and physical stock counts should be carried out on a regular basis to verify stock records.

7. Over a period of 12 months, deliveries of vaccine to the next level have been timely, sufficient and correct.

An effective vaccine distribution system should provide sufficient supplies of vaccine to lower level stores. Deliveries should be made in a planned and timely fashion. Every shipment should be accurately documented by means of a vaccine delivery report.

The earliest-expiry-first-out (EEFO) principle should generally be observed for deliveries. However, store keepers should be able to set aside the EEFO rule whenever VVM status indicates heat exposure. Under such circumstances heat exposed vaccines should be distributed first, regardless of expiry date.

A system should be adopted for managing short supplies.

8. Over a period of 12 months, minimal damage has occurred to the vaccine during distribution.

If correct practices are not followed during vaccine transport, vaccines may be damaged by exposure to excessive heat or to freezing temperatures. When vaccine is damaged in this way, this contributes to increased vaccine wastage and may result in short supplies.

New vaccines, such as Hepatitis B freeze at close to 0oC. Recent evidence shows that vaccine freezing has now become the most serious consequence of poor distribution practice.

A monitoring and reporting system must be in place to ensure that vaccine damaged during transport is identified and replaced before it is distributed to the next level store. This can best be achieved by using electronic data loggers to record storage temperatures during transport. Data loggers should be used for all shipments from primary stores to the first level of intermediate stores, and elsewhere where possible.

9. Over a period of 12 months, the facility has followed standard operating procedures.

Standard operating procedures should be drawn up which are appropriate to each level in the distribution system. These procedures should be presented in a form which can be easily understood by the cadre of staff operating at each level.

Every cold store should be provided with a copy of these operating procedures, and staff should be trained to follow them and to keep appropriate records as evidence of compliance.

  • Standard procedures should cover the following topics:
  • Ordering/requisitioning vaccine;
  • Receiving a vaccine shipment:
  • Managing vaccine during storage, including temperature monitoring;
  • Distributing and transporting vaccines, including temperature monitoring.

10. Over a period of 12 months, human and financial resources have been sufficient.

An effective vaccine distribution system must be properly resourced. Staff must be adequately trained, and motivated to perform their duties. Sufficient recurrent funding must be made available to purchase vaccine and essential consumables, such as fuel and spare parts; to pay and to train staff, and to maintain equipment. In addition capital resources or donor funding must be available to sustain a rolling renewal programme to prevent the accumulation of increasingly unreliable and obsolete equipment.


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