What is a vaccine cold chain?
Vaccines are fragile biological preparations that must take their journey in consistent cold temperatures via a supply chain called a vaccine cold chain. It is also known as a vaccine supply chain or immunization supply chain, according to the World Health Organization (WHO). The vaccine cold chain begins during the manufacturing stage and ends once the patient receives the vaccination. Each step of this cold chain must be precisely orchestrated, so the vaccines remain safe and the cold chain unbroken. The vaccines must be specifically handled during all stages with storage and transport requiring temperature monitoring. Specifics on how to manage the vaccine cold chain are recommended by the WHO and the Centers for Disease Control and Prevention (CDC). These recommendations and regulations are put in place to protect the vaccines and ultimately the patients who will receive them.
According to a WHO report, 50% of vaccines are wasted around the world because of lack of temperature control and the logistics to support the vaccine cold chain. Both the WHO and CDC continually look for ways to refine vaccine cold chain recommendations in hopes to lower this number. Most recently, the use of temperature data loggers is part of the regulations. The WHO also developed three levels and guidelines within each of those levels for handling the vaccine cold chain. Each level has its own set of requirements and equipment. Within these levels, storage and transport handling are critical and temperature monitoring must be used to ensure the temperature required by the vaccine is constant. By ensuring that vaccines are stored and transported within recommended temperature ranges, the vaccines have a better chance of arriving safely to their destination. If the vaccine temperature fluctuates above or below the required temperatures (some vaccines must not be frozen while others need an ultra-low temperature), the active ingredients can be compromised and become less effective and even unsafe. Optimizing the vaccine cold chain could potentially save billions of vaccines per year.
Three levels of a vaccine cold chain
The WHO categorized the vaccine cold chain into three levels: primary, intermediate, and peripheral. Each of these levels require different types of equipment for transporting and storing vaccines. To ensure optimal performance, cold chain equipment used at any level must comply with the technical specifications, as defined under WHO prequalification standards or as determined by national regulatory authorities.
Primary level
The primary level is key requirements for the vaccine cold chain at the national level. This level encompasses a massive distribution from the manufacturer to perhaps a logistics company that uses airlines and trucking companies to take the vaccine to local areas for distribution. Tools and equipment required for this level may include cold or freezer rooms, freezers, refrigerators, cold boxes, and perhaps refrigerated trucks or airplanes to disperse vaccines to many areas around the country. Temperature monitoring is done on a large-scale management and data system.
Intermediate level
The intermediate level concentrates the cold chain information at the district or province point. At this level, the vaccines would most likely be delivered to the hospitals. This level may also use cold and freezer rooms and/or freezers, refrigerators, and cold boxes and refrigerated trucks for transportation.
Peripheral level
The peripheral level focuses on the smaller facilities where the vaccine will be administered such as clinics or pharmacies. At this level of the vaccine cold chain, the tools needed are generally refrigerators (in certain instances with water pack freezing/cooling compartments), cold boxes and vaccine carriers.
At each level, WHO determined specific requirements for how the vaccines should be packaged, shipped, stored, and handled. For example, at the peripheral level there are recommendations for the exactness of how each healthcare professional needs to handle vaccines from the time they arrive at the facility to the time they are injected into arms. These instructions are critical, so the vaccine remains effective until it reaches the patient.
Storage and transport
Within each level of the vaccine cold chain, storage and transport are two of the major steps for logistics management. Anyone involved with managing a cold chain must manage these critical parts of the vaccine cold chain and remain compliant with government regulations. To do this, each link in the cold chain must be accurately monitored with specific digital temperature data logging devices that can save data for future use and audits. These recommendations are located on the CDC website and the WHO website.
Monitoring the vaccine cold chain
The storage and transport temperatures are equally important. The use of temperature data loggers is regulated, and in fact, specific data logging thermometers must be used to monitor the temperatures during vaccine distribution. This list can be found in the CDC vaccine storage and handling tool kit. The WHO also provides its recommendations. Many of these data loggers can be connected to Wi-Fi or Bluetooth® for 24/7 monitoring. The data loggers also offer an easy and secure way to connect a smartphone, tablet, or personal computer so that the monitoring can be done remotely. Storing the data for later use is crucial for auditing purposes.
Summary
The vaccine cold chain is used to distribute vaccines safely from the manufacturer to the patient. Vaccines must be correctly stored and transported with temperature monitoring in place at each step of the way. Specifics about how to manage the vaccines at levels determined by the WHO and CDC for the objective to protect vaccines and the patients who receive them. Within the cold chain storage and transport are critical areas where temperature must be monitored to mitigate risk and keep the vaccines uncompromised.
