Flu season is upon us and laboratories are doing their part to make sure vaccines are prepared and ready for distribution. One of the biggest problems faced by laboratories and clinics during flu season is improper and mismanaged vaccine refrigeration. Vaccines save three million lives per year,1 yet according to the U.S. Federal Vaccines for Children Program, over $20 million worth of vaccines are wasted annually due to improper vaccine refrigeration.
Figure 1 – Smart-Vue wireless monitoring system.Temperatures for refrigerated and frozen vaccines need to be maintained within a strict range, with refrigerated vaccines requiring between 2 and 8 °C and frozen vaccines between –50 and –15 °C. Vaccines such as H1N1 influenza rely on a tight temperature range (2–8 °C), with a desired average temperature of 40 °F (5 °C) and must have temperatures measured twice daily. It is recommended to also use a secondary source of temperature monitoring for maximum product security and peace of mind, such as the Thermo Scientific Smart-Vue™ wireless monitoring system (Thermo Fisher Scientific, Milford, MA) (see Figure 1). Smart-Vue provides independent, secondary monitoring, and comes with the ability to text, e-mail, or call a staff member if the temperature rises or falls outside of the desired range.
Proper vaccine storage and management
Vaccines should be stored in refrigerators or freezers that are large enough to accommodate the highest demand possible as a way to avoid overloading the unit. Vaccines should not be stacked, blocking vents, or positioned where they may fall out of the unit when the door is opened. One should allow for proper air circulation by storing vaccines away from the walls of the refrigerator or freezer.
Figure 2 – Thermo Fisher Scientific High-Performance Refrigerator.During the flu season, one of the busiest times of the year for laboratories, poor weather conditions can lead to power failures. In events like these, it is important to have an emergency plan in place. The plan should include alternate sites for vaccine storage, a list of necessary packing materials, and a proper method of vaccine transportation. Each packing container should have a calibrated thermometer inside of it to monitor the vaccine during transport.
Appropriate vaccine management begins with knowledgeable staff who understand how to use the correct equipment for routine storage and handling of vaccines. Vaccines should be appropriately stored at the correct temperature in refrigerators or freezers designated as “vaccine-only” while awaiting distribution. This means that food or drink should not be stored in the same unit as vaccines. All staff members need to be aware of the guidelines provided by the manufacturer immediately upon delivery. Staff handling vaccines should maintain a detailed inventory log, including information such as the vaccine name, the date the vaccine was created, the condition of the vaccine upon distribution, and the vaccine expiration date.
Recent updates to the CDC storage recommendations support use of purpose-built vaccine storage refrigerators and freezers instead of domestic or commercial refrigeration models. Domestic refrigeration units cannot maintain the uniform temperatures needed to avoid freezing or thawing of vaccines, given that the airflow in these units is neither consistent nor constant. The temperature of a commercial unit can fluctuate as much as 10° during normal use. Purpose-built laboratory refrigerators and freezers have forced air circulation that maintains an even temperature throughout the unit, ensuring that products will see little to no temperature fluctuation during standard use (see Figure 2).
Conclusion
To meet the challenges of flu season, labs need to be prepared to effectively satisfy the demand from clinicians. When handled correctly, monitored closely, and stored in the proper type of cold storage unit, the potency and integrity of vaccines can be protected.
References
- UNICEF; available at www.unicef.org/immunization/index_coverage.html.
- Welte, M. Vaccines ruined by poor refrigeration. USA Today 2007; available at http://usatoday30.usatoday.com/news/health/2007-12-04-spoiled-vaccines_N.htm.
Alex Esmon, Ph.D., is Global Product Manager, Thermo Fisher Scientific, 450 Fortune Blvd., Milford, MA 01757, U.S.A.; tel.: 828-242-0027; e-mail: [email protected].