Billions of doses of vaccines are manufactured worldwide each year to immunize the human population and keep people safe from harmful or even deadly diseases. It is critical that vaccines be safe and effective. The challenges of delivering safe vaccines to the end user, globally or regionally, are many; with one of the most critical challenges being temperature. The slightest temperature fluctuation during the entire vaccine process can change the molecular structure of a vaccine, making it ineffective and potentially harmful. Most vaccines must be either refrigerated or frozen. This requires a temperature-controlled supply chain, known as a cold chain. This cold chain is regulated and must be monitored to ensure vaccines are kept at set temperatures from manufacturing through to when the vaccine is used for immunization. Regulations from the US Food and Drug Administration (FDA) and guidelines from health organizations such as the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and other regional organizations offer guidance documents and tool kits on how to keep vaccines safe during storage, handling and transport along the cold chain. This article focuses on transporting vaccines safely.
The FDA's Center for Biologics Evaluation and Research (CBER) regulates vaccines in the United States and plays a critical role in protecting all ages of people from emerging infectious diseases such as COVID-19. According to the CBER, vaccines undergo a rigorous review of laboratory and clinical data to ensure the safety, efficacy, purity, and potency of these products. Vaccines approved for marketing may also be required to undergo additional studies to further evaluate the vaccine and often to address specific questions about the vaccine's safety, effectiveness, or possible side effects. If you are outside of the US, check with your region’s regulators for the latest requirements to ensure you remain in compliance.
According to WHO, good temperature control during transport of vaccines is critical to ensure their potency and safety. The CDC requires minimal transport for temperature-sensitive vaccines. For example, they suggest vaccines used at an off-site or satellite facility should be delivered directly to that facility, request manufacturers not transport vaccines on a regular basis, and properly pack vaccines for transport. An emergency plan or SOP for transporting vaccines is also recommended with included procedures and protocols for packing and transport. All of this information can be found on the specific organization’s website.
Most vaccines require some type of cold chain. Refrigerated vaccines should be transported at 2°C to 8°C (36°F to 46°F). Frozen vaccines should be transported at -50°C to -15°C (-58°F to 5°F). For example, liquid formulations of aluminum-based vaccines against diphtheria, pertussis, and tetanus, alone or in combination (adsorbed vaccines), should not be frozen. Varicella vaccine and zoster vaccine live must be frozen. MMR vaccines can be stored in the refrigerator or freezer. Once a vaccine is frozen that should not have been, it is compromised and must be discarded. Guidelines are available at WHO and CDC that detail exactly how to transport vaccines that need to be refrigerated and frozen. Such guidelines provide step-by-step instructions on how to keep vaccines safe including what type of freezer to use, the temperature for the freezer, packing instructions, and more.
Accidental freezing of vaccines had been an overlooked problem for many years, prompting researchers to investigate why this was happening. Overall, studies completed found that there was a failure to regulate the cold chain. Some manufacturers were overprotecting vaccines from heat resulting in accidental freezing. These findings resulted in a call for better managing the cold chain by using reliable refrigeration and integrating data loggers to monitor temperature-sensitive items along the cold chain.
According to the CDC, the use of continuous monitoring devices for monitoring and recording temperatures while transporting vaccines is required. In its vaccine tool kit, the CDC offers instructions on how to use data loggers during transport such as how to use the buffered materials and where to place the data logger in the packaging.
A variety of data loggers are available. Select one that helps you to remain compliant, is easy to use and provides proper security protocols. Devices such as the TraceableOne™ and TraceableGO™ data loggers are popular choices for vaccine transport. These products meet regulations because an individually-numbered Traceable® Certificate provided with each unit assures accuracy from our ISO/IEC 17025:2005 (1750.01) calibration laboratory accredited by A2LA. It indicates traceability of measurements to the SI units through NIST or other recognized national measurement institutes (NMI) that are signatories to the CIPM Mutual Recognition Agreement.
What happens if a cold chain is broken? Learn more about the importance of reliable temperature monitoring in this video discussion, How to Store and Transport Your Temperature-Sensitive Samples Safely using advanced tools for cold chain monitoring and compliance.
As the world population continues to be subjected to new viruses and diseases, such as COVID-19, vaccines continue to be researched, developed and manufactured. Billions of vaccines travel the cold chain globally per year, and safety is critical. Temperature remains a top challenge as there is presently no fail-safe equipment to transport vaccines. Monitoring with data loggers has been added to a list of regulations to ensure vaccines remain safe. Failure to do so can result in harm to the end user. To meet this challenge, regulators such as the FDA and health organizations including WHO, CDC, and other regional agencies provide guidance documents and tool kits on how to keep these fragile biologics safe.
Learn more about the vaccine cold chain: The Cold Chain Facilitating Vaccine Distribution