Every year, vaccines prevent between 2 million and 3 million deaths. According to the World Health Organization, as a result of vaccinations administered between 2000 and 2016, there was an 84% worldwide reduction in the number of measles-related deaths. Over the last 10 years, more than a billion children have been vaccinated. Proper handling and storage is necessary to retain vaccine effectiveness.
The justification for handling a vaccine within specific guidelines can be found in understanding its ingredients. Vaccines are biological products, containing proteins, and very often, live (but weakened) viruses. Vaccines typically contain the following ingredients: 1) Antigens: active ingredients, whether live (but weakened) or inactivated, which trigger an immune response. Vaccines work by stimulating a person’s immune system to produce immunity to a specific disease. 2) Aluminum gels or salts of aluminum: adjuvants which encourage a better, more persistent response to the vaccine. Adjuvants minimize the amount of antigen that is needed. 3) Antibiotics: used in some vaccines to prevent bacteria growth during production and storage. 4) Egg protein: found in vaccines which are made with chicken eggs, such as those for flu and yellow fever. 5) Monosodium glutamate (MSG) and 2-phenoxy-ethanol: used in some vaccines to prevent the negative effects of heat, light, acidity or humidity. 6) Thimerosal: a preservative which contains mercury, is used to prevent contamination and harmful bacteria. Most vaccines no longer include this ingredient, however. 7) Suspending fluid: sterile water, saline or fluids containing protein. Vaccines also contain formaldehyde, which is used to kill viruses and bacteria that could contaminate the vaccine during production. Most formaldehyde is removed prior to packaging.
Some vaccines must be refrigerated, while others require freezing. Knowing the specific requirements for each vaccine is crucial for maintaining potency, and avoiding wasted product and lost money. Discovering that a vaccine is no longer effective sometimes occurs after it has been administered. In 2017, Ventura County, California health officials realized that vaccines may have been accidentally frozen prior to being administered. Unfortunately, there was no way to identify who received the bad vaccines, so 23,000 people were alerted and given the option to be re-inoculated. Administering the vaccine to all 23,000 patients a second time, would have cost the county an additional $1.3 million. The impact of disgruntled citizens could result in an even higher price tag.
Before a vaccine can be approved for use, it is heavily tested to ensure it is effective and safe for consumers. With most vaccines, this evaluation period lasts years. During epidemics and pandemics, this testing period can be shortened. The Coronavirus is one example. A COVID-19 vaccine was identified within months, instead of years. Now that we have a viable vaccine, proper handling will be imperative.
The vaccine cold chain is a critical system of requirements, specialized equipment, and procedures, maintained from the time a vaccine is manufactured until it is administered. For a vaccine cold chain to be effective, three elements are crucial: a well-trained staff, an accurate inventory management and reliable storage and temperature monitoring. The cold chain is so important that any temperature excursion can negatively impact a vaccine’s effectiveness. For example, if a vaccine is not meant to be frozen, a single drop in temperature to 32°F or below, can render it completely ineffective. Making matters worse, there is typically no visual indication that a vaccine has been compromised. The life-saving ability of vaccines is too precious to take the risk. Temperature monitoring devices utilized should be appropriate for vaccines, and equipped with alarms, to alert stakeholders to temperature excursions.
Transporting vaccines locally is usually for such purposes as sharing between medical providers, responding to emergencies (SOP’s should be established), moving to off-site clinics or to quickly utilize inventory that is in danger of expiration. These are unique situations, however. Vaccines should not be routinely transported. When transport is necessary, appropriate portable transport units, packing materials and temperature monitoring devices should always be used. If a storage unit will not be available for the vaccines once received at the new location, it is advisable to use a portable vaccine refrigerator during transport. If a portable refrigerator is not available, the following are also acceptable: qualified container packout; conditioned water bottle transport system; manufacturer’s original shipping container (only if no other options are available). Each of these methods should always be equipped with a temperature monitoring device.
In an emergency, certain specific measures should be taken to preserve the vaccine inventory:
- Contact the alternative storage facility to prepare for transported vaccines;
- Only open refrigerator unit when ready to pack, or power is restored;
- Suspend vaccinations to prepare for transport whenever an emergency is anticipated, such as bad weather.
Shipping vaccines over long distances, such as with the Coronavirus vaccine, involves unique considerations. For example, the recently approved Pfizer’s COVID-19 vaccine, must be stored and shipped at -70°C. In order to maintain the appropriate temperature, the company is using special shipping containers which hold 20 pounds of dry ice pellets. Once received by healthcare providers for dispensing, there are special requirements for storage such as frequent addition of dry ice pellets to the storage container, and a limit on the number of times the container may be opened. Vaccines from Moderna and Astra-Zeneca will require transport and storage at 20°C and 2-8°C, respectively.
Now that Coronavirus vaccine distribution is in full swing, the FAA’s COVID-19 Vaccine Air Transport Team, established in October 2020, will respond to any issues surrounding air transport, and ensure shipping will continue 24 hours a day. Temperature monitoring devices specifically designed for use with various temperature profiles will be required in managing the COVID-19 vaccine cold chain. Given the speed at which COVID-19 vaccine distribution is occurring, real-time monitoring enables stakeholders to take decisive action if temperature excursions are observed. Forgetting to activate a data logger, as can frequently happen in fast-paced environments, is no longer the end of the world, thanks to patented features like Shadow Log. DeltaTrak provides multiple solutions to meet your vaccine transport and storage needs. Contact your DeltaTrak sales professional for more information.
World Health Organization, https://www.who.int/en/news-room/fact-sheets/detail/immunization-coverage , July 15, 2020.
World Health Organization, https://www.who.int/campaigns/immunization-week/2018/en/ , 2018.
World Health Organization/GAVI Alliance. Module 2: Vaccines and Drugs: Similarities and Differences, https://isoponline.org/wp-content/uploads/2015/10/Differences-on-drugs-and-vaccines.pdf , 2015.
Heredia Rodriguez, C. “Vaccines are Sometimes Stored Improperly, Reducing Their Effectiveness”, USAtoday.com, https://www.usatoday.com/story/news/health/2019/02/11/cdc-vaccines-children-stored-improperly-mishandled-reduce-effectiveness-dhhs-measles/2811629002/ , February 12, 2019.
Weise, E and Aspegran, E. “FAA Confirms First ‘Mass Air Shipment’ of Pfizer’s COVID-19 Vaccine from Belgium As US Preps for Distribution,” https://www.usatoday.com/story/news/health/2020/11/29/pfizer-covid-vaccine-faa-belgium-air-shipment/6445339002/ , November 29, 2020