Vaccines are one of the greatest innovations of modern medicine, virtually eradicating deadly diseases like smallpox and polio. But, in order for vaccines to work effectively, stringent handling, transport, and storage guidelines must be precisely followed.
Vaccines are fragile biologics, and even slight temperature changes can alter their molecular structure, rendering them ineffective or toxic. More than 90% of all vaccines require a temperature-controlled supply chain (the “cold chain”) that begins with the manufacturer and ends with the administration of the vaccine to the patient. A breakdown at any point in the chain can lead to time-consuming testing, recalls, and waste.
One of the issues facing cold chain transport is the globalization of healthcare. While technology has made the relative distance between regions of the world much smaller, when it comes to vaccine transport and temperature controls, the physical distance a product must travel is wrought with potential pitfalls. The reality is, it takes time and coordination to efficiently transport a vaccine from point A to point B, and even a small delay or equipment failure can have negative consequences for all stakeholders.
Cold Chain Safety – a Shared Responsibility
The cold chain process begins with the cold storage unit at the manufacturing plant, extends through transport of the vaccine to the distributor, followed by delivery and storage at the provider facility, and culminates with administration of the vaccine to the patient.
One of the challenges of the cold chain system is that it contains many “links”, and all are subject to the potential for human error and equipment malfunction. Vaccine efficacy is the shared responsibility of all who handle the product from the time it is manufactured to the time it is administered. When breakdowns occur, the consequences can be costly and potentially harmful.
The Centers for Disease Control and Prevention (CDC) in the U.S., and the British Columbia Centre for Disease Control (BCCDC) in Canada, have developed vaccine storage and handling guidelines. The recommended best practices include:
- Storage and handling methods for refrigerated and frozen vaccines
- Considerations for equipment such as storage units and thermometers
- Strategies for maintaining the cold chain
- Routine storage and handling practices
- Inventory management and emergency procedures for protecting vaccine inventories
Each best practice step requires detailed standard operating procedures and log books. Considering the number of steps involved and their complexity, it is easy to see how errors can occur. In general, the success of the cold chain is dependent on well-trained personnel, reliable transportation, efficient management procedures, and proper storage equipment.
Safety Strategies, from Storage to Delivery
Specific storage unit guidelines for vaccines include the recommendation of stand-alone units that either refrigerate or freeze the vaccine. These recommendations are based on a 2009 NIST study which demonstrated that stand-alone or pharmaceutical units maintain required temperatures better than household/commercial combination units.
Most combination household refrigerator/freezers have a combined temperature control unit that can create cold spots and temperature fluctuations in the refrigerator portion of the unit, putting sensitive vaccines at risk. Improper storage of vaccines is a problem in Canada as well – recent inspections of refrigerators in healthcare provider premises have shown that improper storage and handling of vaccines is a significant problem in Ontario.
When it comes to the transport of fragile vaccines, there are guidelines for containers and packing materials, specific guidelines for vehicles and drivers, and a need for alternative plans in the event of inclement weather. These guidelines include the use of a calibrated temperature monitoring devices with continuous monitoring and recording capabilities during transport. Companies transporting vaccines also need to consider variables that include:
- The type of vaccine
- The climate/seasonal temperature
- The amount of vaccine being transported
- The container
- Packing material and pack out method
- The number of times the container will be opened and closed
In addition to maintaining the cold chain, vaccine providers face a separate challenge of verifying any lapses in the chain and in testing the viability of the vaccine before it is administered – a daunting prospect even in industrialized countries like the U.S. and Canada. Even with adherence to all of these best practices, a vaccine’s efficacy can be compromised by outside forces such as power outages, travel delays, and simple human error.
Counting the Cost: Vaccine Wastage
Any vaccine that cannot be used due to damage or expiration is considered “wasted.” Excessive heat, cold, or light exposure can damage vaccines, resulting in reduced potency. Once potency is lost, it cannot be restored. Each time vaccines are exposed to improper conditions, potency is reduced further. Eventually, if the cold chain is not properly maintained, potency will be lost, and the vaccines become useless.
The Advisory Committee on Immunization Practices (ACIP) recommendations state that mishandled vaccine doses should not be counted as valid doses. ACIP advises that it is better to not vaccinate than to administer a dose of vaccine that has been mishandled.
In some cases, inappropriate storage or transport may lead to a vaccine recall. This can result in extra doses for patients, increased costs for providers, and even damage to public confidence in vaccines. Vaccine inventories are very expensive, and the costs associated with loss and replacement and resources necessary to conduct a recall can be significant.
The Need for New Technology
The vaccine pipeline is rife with promise. There are currently more than 271 vaccines for infectious diseases, cancer, neurological disorders, allergies, and other diseases in development. The introduction of so many new vaccines will require new thinking on the way vaccines are manufactured, stored, and delivered. For example, many newer vaccines are often in single or two-dose packages. While this helps to reduce waste, it also means that they require more cold chain space per dose.
The need for more cold storage space presents a challenge in developing countries where temperature-controlled storage units are in limited supply. The World Health Organization (WHO) estimates that reliance on the cold chain increases vaccine costs by up to 20% and poses a significant barrier to patient access in many emerging markets. The development of vaccines that do not require refrigeration has the potential to dramatically change the availability of vaccines to underserved populations around the world.
VBI’s Thermostable Platform
As an alternative to reliance on the cold chain, VBI’s thermostable LPV™ technology platform enables the development of vaccines and biologics that can withstand storage or shipment at constantly fluctuating or elevated temperatures. Once commercialized, this technology could increase vaccine safety, efficacy, and access in both established and emerging markets. To learn more about our thermostable technology, contact us.