Vaccines are biological products. If they become too cold or too hot (some formulations should not be frozen), their active ingredients will degrade, making the vaccines less effective. As soon as the manufacturer prepares the vaccine dose, they transport it to health centers, clinics, and immunization programs around the globe. The doses must be viable until when needed.
To preserve vaccines, keeping them at the correct temperature as they move from the manufacturers to syringes, a vaccine cold chain equipment is necessary. In this article, we will tell you what a vaccine cold chain is and how it functions.
What Is a Vaccine Cold Chain?
A cold chain is a vaccine storage system adopted to ensure that vaccines remain in proper condition. It can also be called a supply chain for immunization. This system was designed to maintain a standard according to the requirements of the World Health Organization (WHO).
These requirements include temperature ranges monitored from the time of departure to the time of administration. Additionally, the supply chain for immunization is a universal network of carriers, cold boxes, refrigerators, freezers, and cold rooms.
Types of Cold Chain Equipment
The types of equipment for transporting vaccines are:
Refrigerators used in health facilities have different power sources, some of which include electricity, gas, and solar energy. Choosing a class of refrigerator for use in health facilities should be focused on the most efficient means of energy supply. The use of domestic refrigerators for storing vaccines is not recommended as their temperature cannot be regulated.
In addition, they cannot maintain a cool temperature for the vaccines when there is a power outage for more than three hours. This is because such refrigerators were not designed for vaccine storage. The different types of refrigerators for vaccine storage are:
This type is known as a compression unit. In a place where there’s reliable power supply, an ice-lined refrigerator would be the best option. Here, the refrigerator’s inner lining can keep the vaccine at a temperature range of over 2 degrees Celsius to 8 degrees Celsius in cases of periodic power failure. On the other hand, if vaccines aren’t properly loaded in this refrigerator it might result in the freezing of vaccines.
This is also called a photovoltaic unit. It is quite expensive to purchase and install compared to the electric refrigerator. On the brighter side, it does not incur any running costs like electricity bills, apart from the cost of maintenance and cleaning. You can visit this website to read more about solar-powered refrigerators.
This is also known as an absorption unit. It is very useful in areas where the sunshine is insufficient for solar units or there’s no electricity. Using a gas-powered refrigerator is preferred to the kerosene- powered type because it requires more maintenance and less temperature control.
2. Cold Boxes
These are insulated containers that have water packs as their inner lining. They are useful when you want to keep diluents and vaccines within a specific temperature when you are in transit or storing them for a short period.
Additionally, the boxes come in different models. Some allow you to store items for about 2 or more days when:
- There’s no electricity.
- The refrigerator in the health center is not functioning.
- The refrigerator is defrosting, and you need passive containers.
After packing the vaccines into the boxes, you shouldn’t open them until you want to administer the doses. The boxes can maintain a temperature range of fewer than 10 degrees Celsius if they remain closed and are lined with frozen packs of ice.
Health centers should choose cold boxes based on these factors:
- The storage capacity they need for the period of supply.
- The required cool life, depending on the period of storage, including time spent on transport.
- The number and type of water packs that can fit the sizes of the boxes.
3. Vaccine Carriers
These are smaller carriers compared to cold boxes. They are very easy to carry and are used for the following:
- Transporting diluents and vaccines to immunization sites and storing them during immunization sessions in health facilities.
- Temporal vaccine storage when the refrigerator in the health center is defrosting or not functional.
- Transporting vaccine supplies monthly from district stores to small centers.
Health centers should choose vaccine carriers based on these factors:
- The quantity and type of diluents and vaccines they want to transport.
- The required cool life for the journey.
- The method of transport (for instance, transporting vaccines on foot for a short distance won’t be the same as transporting them on a motorcycle during a long-distance journey).
There are other types of vaccine cold chain equipment. You may want to visit http://helid.digicollection.org/en/d/Js2979e/4.3.html to read more about it.
Most vaccines should not be kept frozen. They just need to be cold. While this sounds simple, it is not easy in real life. Imagine moving around the desert with a cold bottle of water and it does not heat up. In practice, the cold chain has lots of challenges particularly when you want to reach rural or remote communities where electricity is not reliable.