Vaccines and Cold Chain

Victoria, NSW and ACT allow pharmacists to administer vaccines as part of a mobile or outreach setting on behalf of a service provider (hospital, pharmacy, pharmacy depot). A mobile vaccination service spans several days and involves long distance travelling to provide immunisations at different sites. An outreach vaccination service spans for several hours and the pharmacist administering the vaccine returns to the service provider before the end of the day. Cold chain management is vital when offsite vaccination services are offered.

Vaccines must be stored between 2 to 8 degrees Celsius from when it is manufactured to when it is administered. A higher temperature range would result in a reduced shelf life of the vaccine whilst freezing temperatures may lead to irreversible loss of vaccine potency.

When vaccines are removed from the refrigerator in the pharmacy for offsite delivery, a portable insulated container (polystyrene cooler, domestic cooler, vaccine carrier, vaccine cold box) is used for transporting it.

The cold life of a container is the time taken for the internal temperature of a portable insulated container to reach +10 degrees Celsius after ice packs have been added and the lid is closed at a constant ambient temperature of +43 degrees Celsius. Choice of container used for transportation of vaccines is based on the cold life as follows:

• Polystyrene coolers are only suitable for up to 4 hours
• Domestic coolers or Esky are suitable for up to 8 hours
• Short range vaccine carrier for a minimum 15 hours
• Long range vaccine carrier for a minimum of 30 hours
• Short range vaccine cold box for a minimum of 48 hours
• Long range vaccine cold box for a minimum of 96 hours

Vaccine carriers are small, light and can be carried by a single person and so are more commonly used than cold boxes.

Portable insulated containers are not powered and need ice packs/bricks or gel/cold packs to lower the temperature inside them to 2 to 8 degrees Celsius. It is necessary to condition the ice/gel packs before placing them in a portable insulated container for vaccine storage. This is to reduce the chance of the vaccines freezing and losing their potency. Place the ice pack in a freezer for > 24 hours. Only ice packs that are frozen solid should be conditioned and used.

Conditioning ice packs:

Lay the ice packs in a single row with at least 5cm space between the packs (allows maximum air exposure) and expose the surface to room temperature. Wait till the ice packs sweat (condensation of droplets of water on the outside of the packs). This takes about an hour at an ambient temperature of 20 degrees Celsius. Shake and listen for the slight slosh of water inside the ice pack to confirm that the ice pack has been conditioned appropriately.

Conditioning gel packs:

Refer to manufacturer’s instructions as there is a difference in the types of ingredient used to depress the freezing point of the gel pack. Some specialised vaccine cold boxes (e.g. Coolpac45) come with their own gel packs which do not require conditioning. Many gel packs do not come with manufacturer’s instructions. In such cases, the following guide can be used:

• Gel packs weighing < 750g and room temperature > +15 degrees Celsius, condition for around 45 minutes (60 minutes if room temperature < +15 degrees Celsius).
• Gel packs weighing > 750g and room temperature > +15 degrees Celsius, condition for around 60 minutes (90 minutes if room temperature < +15 degrees Celsius).

Generally gel packs take slightly longer than ice packs to condition. The number of ice/gel packs required depends on the size, type and capacity of the cooler, the number of vaccines being transported, and the type of ice/gel packs used. Every pharmacy should have a minimum of two sets of ice/gel packs for each passive cooling device. One set in the freezer and the other set in the portable insulated container.

Lower the inside temperature of the portable insulated container to 2 to 8 degrees Celsius with frozen non-conditioned ice/gel packs before placing the vaccines. This usually takes several hours. Use a min/max thermometer to ensure that the appropriate temperature range has been achieved.

When packing the portable insulated container, it is necessary to place insulating material (polystyrene chips, bubble wrap, crumpled packing paper) between the ice/gel packs and vaccines. A single layer of paper towel is not adequate to protect the vaccines from inadvertent freezing from the ice/gel packs. For small portable insulated container, place conditioned ice/gel packs at the top and close and seal the lid. For larger portable insulated containers, place ice/gel packs along the vertical walls of the container and on top.

The vaccines should be transported in their original packaging. Place a min/max thermometer probe in the middle of the vaccines. The portable insulated containers should be monitored every 15 minutes for the first 2 hours while the temperature stabilises, and then every hour with the min/max thermometer. This should be recorded on a temperature chart. The min/max thermometer should be reset after each reading. If there is a purpose built vaccine refrigerator at the outreach or mobile site, the vaccines should be transferred from the portable insulated containers to the refrigerator. If there is no refrigerator, then the pharmacist should take additional ice/gel packs to replace the melted ones in the portable insulated container if the need arises. If vaccines are outside, they should be kept away from direct UV light and sunlight to reduce potency loss

Pharmacists have a professional responsibility to administer efficacious and immunogenic vaccines. Breaches in cold chain management may leave the individual and community at risk of vaccine preventable diseases. If a breach occurs, the Department of Health should be notified using the cold chain breach report form as soon as possible. It is vital that the mobile or outreach service is planned carefully.