Using Temperature Monitoring Devices to Improve the Cold Chain for Vaccines

Proper vaccine storage and handling have been an essential factor in preventing and eradicating many common vaccine-preventable diseases. Failure to regulate a vaccine’s temperature can reduce its potency, resulting in inadequate immune responses in patients and reduced protection against diseases. Providers in Vaccines for Children [VFC] programs must pay close attention to the cold chain to prevent vaccines from being exposed to temperatures outside the recommended ranges.

Temperature Monitoring Devices (TMDs) eliminate this problem by providing accurate information from monitoring temperature conditions inside refrigerator and freezer storage units.

The Challenges of Poor Maintenance of Cold Chain for Vaccines

The cold chain is a temperature-controlled environment used to maintain and distribute vaccines in optimal conditions. It begins with the cold storage unit at the manufacturing plant and extends through transport of vaccines to the distributor. From there, vaccines are delivered to and stored at the provider facility. The cold chain ends when the vaccine is administered to the patient. It is essential to appropriately handle and store vaccines at every link in the cold chain.

Too much exposure to heat, cold, or light at any step in the cold chain can damage vaccines, resulting in loss of vaccine potency. Each exposure to abnormal conditions further reduces the vaccine’s power.

While exposure to any inappropriate conditions can affect the potency of refrigerated vaccines, a single exposure to freezing temperatures (0° C [32° F] or colder) will destroy some. For example, liquid vaccines that contain an adjuvant can lose potency when exposed to freezing temperatures.

Storage and handling errors can cost thousands of dollars in wasted vaccine and revaccination. They can also result in the loss of patient confidence when repeat doses are required.

One of the limitations to measuring temperatures in a vaccine storage unit is the use of certain types of TMDs, like alcohol or mercury thermometers, bi-metal stem TMDs, food TMDs, chart recorders, infrared TMDs, and TMDs that do not have a current and valid Certificate of Calibration Testing. These devices can be challenging to read and, because they only show the temperature at the exact time they are checked, may fail to detect temperatures outside the recommended range.

The Centers for Disease Control and Prevention (CDC) published the Vaccine Storage & Handling Toolkit in January 2018 to assist state and individual VFC providers in properly storing and handling their vaccine supply. In this toolkit, the CDC recommends the use of a specific type of TMD known as a Digital Data Logger (DDL) for continuous temperature monitoring and recording.

The Benefits of Using a Digital Data Logger (DDL)

Some significant benefits emerge when using DDL devices for continuous temperature monitoring and recording, including:

• Monitors vaccine temperatures more closely than standard thermometers
• Simplifies the reading records by removing false alarms
• Eliminates the need to constantly download the readings recorded
• Notifies staff members of out-of-range temperature situations
• Allows use of the device for either refrigerated or frozen storage
• Extends the life of the DDL device by providing a service to recalibrate it, change the battery, and perform annual maintenance
• Enables staff members to know when the device needs its battery changed
• Improves the measurement and recording of temperatures by allowing the logging interval (or reading rate) to be programmed

What to Look for in a Solution Provider

When looking for a company to integrate a DDL into a facility, consider the following requirements:

• Manufactures all types of portable test instruments. Seek a company with proven experience in the development and production of temperature-monitoring solutions.
• At least ten years’ market experience. Try to find a company that has been working with temperature-monitoring solutions for at least ten years and has a variety of customers and extensive knowledge.
• Offers certified calibration services. Look for a company that brings those services to support compliance, traceability, validation, and quality assurance programs.
• Compliance with CDC rules. The right solution should be compliant with CDC regulations that went into effect in January 2018.
• Compliance with the Code of Federal Regulations (21 CFR Part 11). Look for a solution that provides an accurate reading, programmable alarms and sampling intervals, and a USB connection to quickly and easily download temperature data.
• Easy to use. Be sure the device comes preconfigured and can easily be attached to the outside of the storage door, while the sensor bottle is placed inside, allowing users to read current and minimum/maximum temperatures without opening the unit.

The DeltaTrak Solution: The FlashLink Certified Vaccine USB PDF Data Logger

DeltaTrak has more than 27 years of experience as a leading innovator of end-to-end cold chain solutions for the produce, food, and life science industries. The company specializes in temperature and humidity monitoring and recording systems, product emulation capability, and cloud-based services that give 24/7 visibility to real-time actionable data.

The FlashLink Certified Vaccine USB PDF Data Logger has the following features:

• Compatible with CDC guidelines
• 21 CFR Part 11 compliant
• Single-channel, external sensor in glycol bottle
• Automatically generates encrypted PDF, CSV, and daily log reports
• Glycol-buffered sensor emulates products and prevents false alarms
• Can be used to monitor vaccines and liquid medicines during storage
• Audible and/or visual alarms
• Low-battery indicator on LCD
• Quick disconnect cable to download log
• User programmable: manual or auto start, logging intervals, hi/low alarms
• Scroll through recorded data on LCD

The Model 40527 includes an ISO 17025 Calibration Certificate from the American Association for Laboratory Accreditation, valid for two years. Reference standards traceable to International System of Units (SI) through the National Institute of Standards and Technology (NIST).

To take the first step toward improving the temperature monitoring and recording of your vaccines, call 1–800–962–6776 or e-mail salesinfo@deltatrak.com.

About Author

Jorge Luis Alonso G. is writer and journalist. He writes white papers, articles, and blog posts for high-tech industries. He is based in Argentina.