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Flu season: Vaccine transportation

Updated: Mar 16, 2022

Transporting vaccines safely is a complex & difficult task. It is essential to keep the vaccines at optimum temperature, and there are many guidelines from different agencies such as Public Health England on how to store, transport and thus maintain their effectiveness.

At CorrMed we excel at designing and manufacturing medical bags. During 2020 we have been working hard to provide new improved vaccine bags with infection control and usability design features at their core. However, it is equally important to ensure the cold chain is maintained and the temperature of the contents stays between 2-8°C.

An option is to consider polystyrene boxes, however the challenges here are that the boxes are bulky in nature. This means that they often don’t fit into the car of the Community Nursing team and are difficult to store when they aren’t in use. In addition, polystyrene is not wipe clean or anti-bacterial which makes it hard for the team to maintain their infection control standards. This is one of the reasons why the Porta thermal bags are so good; they are collapsible and thus can be easily stored, are wipe clean using anti-bacterial and anti-fungal materials which is essential for infection control standards. The Porta thermal bags are also made using 250D tarpaulin, YKK zips and metal fastenings which means that they are extremely durable.

The durability of a vaccine bag is essential, but so is the cold chain. For many vaccination teams, they will load up the vaccines into their transportation bags first thing in the morning, before heading off for a remote clinic whether it be in the school, village hall, nursing home or at-home visits. The golden question so many vaccination teams ask is “how long will it keep the contents between 2-8°C?”.

There are so many factors which affect the temperature of the contents of a cold chain bag and the length of time they will remain between 2-8°C, to name but a few: thermal properties of the contents, ambient temperature, packing of contents, number position and type of coolant used, plus the temperature of content when placed into the bag.

We can’t test for all variables, but the R&D team at CorrMed spent the summer working with an independent testing company, Cambridge Refrigeration Technology, and together we tested a number of different scenarios to help provide a useful guide for our customers. We have used frozen coolants, no coolants and also chilled coolants, we have changed the coolants used and their positions in the bags, we have tested using both 30°C ambient and 25°C ambient temperatures, and finally we have tested with contents being loaded at 2°C and also at 5°C.

The results are fascinating, and the full report can be made available upon request. The longest time below 8°C maintaining the cold chain was with a test carried out on the 20-litre thermal bag with 2 large coolant blocks and 6 coolant gels. The contents remained in cold chain for 9.98 hours. Yet another 20 litre thermal bag, packed differently, gave a time of 6.3 hours. The only difference was the number of coolants used. Our assumption is the extra coolant at the top of the bag has absorbed the incoming heat, providing a protective barrier for the contents within. The results then make us ponder how the bags would have fared if we also our had our thermal pillow in place, this would surely have helped even more.

Ultimately there are so many varying factors, the key ingredient other than a well-built bag which can carry the weight and protect the contents, is the inclusion of a data logger, to keep track of the temperature of the contents and to audibly alarm should a breach be imminent so proactive measures can be put in place to maintain the cold chain.

The full range of Porta Thermal Cold Chain Vaccine Bags created by CorrMed can be viewed here


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