How to Preserve Vaccine Products During a Power Failure: Case Study

Introduction: Tracking Vaccine Storage Temperatures

For optimal vaccine efficacy, storage temperatures must be maintained within the manufacturers’ specifications at all times. Vaccines stored at temperatures outside of this range are a public health concern. However, lapses in storage conditions occur worldwide and appear in the mainstream media several times per year.

During the summer of 2008, several clinics run by a national research hospital in the United States suffered power failures caused by storm damage.

The pediatric clinics operated by this hospital administer more than 60,000 routine childhood vaccinations each year, participate in the “Vaccines for Children” program, and are accredited by The Joint Commission (formerly JCAHO).

Both the VFC and The Joint Commission require complete documentation of drug and vaccine storage temperatures, including corrective actions taken if storage temperatures go out of range.  While Joint Commission accreditation standards require twice daily recording of storage temperatures, the VFC programs in some states require continuous monitoring. 

Problem: Adequate Equipment for Vaccine Storage

If a vaccine is exposed to temperatures outside of the range indicated on the product label, the FDA states that these vaccines must be discarded (see the CDC's Vaccine Management Recommendations). The manufacturer’s data will usually specify the storage temperatures a vaccine can tolerate and still maintain its effectiveness.

In some instances, a brief temperature excursion will change the expiration date of the affected product. Very few vaccines maintain efficacy once temperatures drop below 1°C.

Domestic (kitchen-style) refrigerators are inadequate for storage in both the refrigerator and freezer compartments simultaneously. This may be due to the fact that there is a single compressor for both compartments. Even relatively new domestic refrigerators can become too cold if the freezer maintains temperatures of -15 °C.

Studies of vaccine storage in physicians’ offices have shown that there are frequent problems with vaccine storage temperatures being outside of the acceptable range.

Alternative Solutions for Vaccine Temperature Monitoring

The common method for monitoring temperatures in many clinics is to check and manually record the temperature in the refrigerator once or twice daily. The flaws in this method include a reliance on busy office staff to remember to log the temperatures, the possibility of recording the wrong temperature, or staff recording out-of-tolerance temperatures without registering a problem.

In one instance at the hospital in this case study, a member of the nursing staff had manually logged temperatures that had gone out of tolerance for several days in a row. Although the log specified the acceptable range temperature as 2-8 °C, staff mistakenly believed temperatures to be within specifications.

Once the error was discovered, hundreds of parents and guardians were notified that their children may have received ineffective vaccines and were given the option of having their children re-immunized at no cost.

Previously, the clinics used graphing thermometers to meet the VFC requirement. The graphing thermometers had occasional mechanical problems (e.g., the pen would be bumped causing data to be recorded incorrectly). Battery failures would go unnoticed for several days causing gaps in the data.

In addition, when the paper was not changed weekly as needed, the previous week’s data would be obscured as the current week’s data was recorded over it. The cost of the recommended annual calibration for these thermometers ($150) was more than ½ the cost of purchasing a new unit ($250).

Implementing an Emergency Plan for Vaccine Preservation

In 2007, the clinics implemented several measures to ensure safe storage of vaccines.  First, Thermo Fisher Scientific Forma Model 3768 pharmacy refrigerators and freezers were purchased for each clinic. 

Then, the Veriteq temperature monitoring and alarm system viewLinc™ was installed to record temperature data and responses. The Veriteq system connected to the facility’s remote central server. (Figure 1)

The viewLinc system sends alarms via email, phone, PC display or text pager when temperatures go out of established ranges or when communication failures occur between the sensor and the server.  These communication failures may indicate a power outage. 

Figure 1. Vaccine Fridge/Freezer Monitor viewLinc Connectivity Options

Click the diagram for a larger view.

During a power outage, the battery back up in the data logger will allow the temperature data to continue to be continuously recorded. Once the power is restored, then the temperature data on the data logger may be transferred to the server for review.

>>more on viewLinc™

Saving Vaccines During a Power Failure

On Friday, June 27, 2008, a severe thunderstorm with winds of up to 100 mph moved through the area surrounding the research hospital and its affiliated clinics, causing widespread power outages. Several clinics lost power. The viewLinc monitoring system sent communication-failure alarms via text message to designated staff and notified the Pharmacy Director.

Staff quickly coordinated a plan to move all frozen and refrigerated vaccines to clinics that still had power. Staff placed frozen ice packs or bags of cubed ice in the refrigerators to help maintain temperatures until the vaccines could be moved.

Before this incident, protocol for managing power outages stated the pharmacist on-call would coordinate the movement of the vaccine to one central location. However, the scope of the storm damage made this approach impractical.

The Pharmacy Director and the Pediatric Clinic Director made the decision to move the vaccine from an affected clinic to whatever clinic was closest and still had power.

The vaccines were packed with ice packs and marked to indicate the clinic of origin. Fallen trees and power lines made traveling difficult in some parts of the city, but the entire move from the time that the power failed until the time that the vaccine was secured in clinics that had power took less than 4 hours.

When power was restored, the viewLinc system sent text messages indicating that the communication failure between the clinic and the server was resolved. Temperatures recorded by Veriteq data loggers were automatically uploaded to the server.

The Pharmacy Director reviewed the records and determined that the storage temperatures had stayed within acceptable ranges prior to being transported.

For refrigerated vaccines, the time that temperatures were out of range was considered to begin when the temperature rose above 8°C and to end when the vaccine was packed with cold packs or ice.

For frozen vaccines, the time period that temperatures were out of range was considered to begin when the temperature rose above -15°C and to end when the vaccine was packed in the cooler containing dry ice.

Creating a Vaccine Preservation Plan for Emergencies

"I have yet to be in a game where the most prepared team didn't win."
- Urban Meyer (1964-)Head Football coach at University of Florida

Based on this experience of multiple simultaneous power failures, clinic staff has taken several steps to safeguard vaccines during similar emergency situations.

Arrangements were made with a local distributor to have regular deliveries of dry ice. In a wide-spread power failure, dry ice may quickly become unavailable, as it will be kept by most retailers to preserve food. Regular deliveries ensure it is always available for medication and vaccine storage.

In addition, all clinics are now equipped with emergency kits containing:

• Two large coolers with wheels for transporting vaccine. One for refrigerated product and one for frozen product;
• Baggies and stickers color coded for each clinic;
• A list of the nearest location(s) of dry ice including the nearest clinic where dry ice is being stored;
• A log to record dates and times that the vaccine is moved between the refrigerator or freezer and the coolers.

>>> See The Center for Disease Control's recommendations for power failure preparation planning.

Measured Benefits: Proper Equipment & Preparation

The implementation of purpose-specific medication refrigerators for vaccine storage and a continuous, network-based temperature monitoring system has had multiple positive effects.

First, it allows clinic and staff to be confident that the vaccine products they administer have been stored in a manner that ensures the effectiveness of the vaccine.

In addition, the new contingency plan has given the organization a way to safeguard vaccine stores against loss during extraordinary circumstances. When power failures occur, the temperature monitoring system provides data that allows the organization to make evidence-based decisions on product viability.

For more information on Veriteq's viewLinc Temperature Monitoring System, please email customersupport@veriteq.com or call 800-683-8374.