Pfizer’s recent announcement that they might have a functional vaccine has raised questions regarding how it will be distributed if/when approved. The storage and handling guidelines can vary depending on the nature of the vaccine, which can also require various labeling solutions. Here we will cover the best practices for identifying, storing and handling the multiple vaccines currently being developed against COVID-19.

Vaccine labeling best practices

There are strict regulations concerning vaccine labeling requirements, comprising the content and format of the label. The label must contain all relevant information, including if they require reconstitution with a diluent before use, as well as a warning section. This warning section should describe any severe adverse reactions, potential safety hazards, and situations in which the drug must not be used. It is also important that the package include an insert that details use instructions, precautionary information, and safety warnings. If new information comes to light, labeling should be revised to include the latest data. The storage conditions of the vaccine should also be considered as refrigeration versus freezing requires a different label. Deep freeze labels will suffice for refrigerated vaccines; however, when freezing is needed, the use of cryogenic labels is necessary to ensure they don’t fail, rendering the vaccine unusable.

Regarding storage, labeling can also help improve organization and ensure all staff is clear on the proper use and handling of the vaccines. Given that a refrigerator may hold various vaccine brands and formulations, labeling the storage area, from shelves to the containers themselves, can help staff quickly locate and choose the correct vaccine, reducing the possibility of administration errors. Color coding and vaccine warning labels can also provide a visual aid and further enhance vaccine organization. If the vaccine must be reconstituted before administration, reminders can be posted to ensure this step isn’t skipped. Labels can also be used to indicate the beyond-use date. They can be placed directly on the packaging; however, the vial is the safest place to put the label in case it is inadvertently placed in the wrong box. In addition, vaccines exposed to a cold chain incident should be clearly labeled, with exposed vaccines placed in a container marked “DO NOT USE”.

Cold temperature storage

Vaccines typically fall under two categories in regards to storage temperature; refrigerated vaccines and frozen vaccines:

The optimal temperature range for refrigerated vaccines falls between +2°C and +8°C (+35°F and +46°F). Protection from light may also be a consideration, but only for certain vaccines. Refrigerated vaccines are generally virus-based, using a viral vector to deliver a protein subunit into the body that will confer the appropriate immune response. Unlike frozen vaccines, they must never be exposed to freezing conditions as they can become inactive, lose potency, or become unusable. Refrigerators built for the purpose of storing vaccines are highly recommended, particularly when storing large inventories. This is primarily for the temperature regulation mechanisms these refrigerators offer, as well as the improved air circulation. Features that are not available in traditional kitchen and bar refrigerators.

Frozen vaccines should ideally be kept between –15°C and –50°C (+5°F and -58°F) in a stand-alone freezer used for that purpose. Similar to refrigerator vaccines, they can be light-sensitive and should be kept away from direct light. This is also the case for the recently announced vaccine from Pfizer and BioNTech. Frozen vaccines, like the one from Pfizer, are based on messenger-RNA (mRNA) that can elicit an immune response in the body. However, mRNA is relatively unstable and requires lower temperatures to remain functional.

Here are some tips to help ensure vaccines are safely stored:

• Always store vaccines in their original packaging when possible. This protects them from light exposure, reduces the possibility of administration errors, and simplifies the process of tracking expiration dates.
• Water bottles can be placed in both freezers and refrigerators to help maintain stable temperatures. They should be labeled “DO NOT DRINK” for obvious reasons.
• Vaccine labels should be used to clearly and accurately identify shelves and containers storing vaccines and diluents.
• Vaccines and diluents should be stored in rows, allowing adequate space between adjacent rows as not to impede proper airflow. Also, vaccines should never be stored on the door, as this is the area that experiences the most significant variation in temperatures.

Labels should be used to clearly and accurately identify shelves and containers storing vaccines and diluents.

Temperature monitoring devices & emergency protocols

The use of temperature monitoring devices is essential for proper temperature monitoring of vaccines. Staff should routinely monitor the temperature of refrigerators and freezers, with one person designated as the lead, to ensure vaccines are kept at the required temperatures. Monitoring devices assist in this process as they can be calibrated to within ±1°C accuracy and alert staff if there are any deviations. This is important as visual inspection is not always enough. For instance, vaccines inactivated due to exposure to freezing temperatures may not appear frozen, despite their reduced or lost potency. Some commonly used devices include digital maximum-minimum thermometers that provide three readings, the current temperature, and the minimum and maximum temperatures that have been reached over time. Another useful tool is data loggers, continuous temperature recording devices, which offer a historical record of refrigerator temperatures, and can print readings out weekly.

There should also be a contingency plan for vaccine storage in the event of equipment failures, power outages, or natural disasters. Clear and concise procedures should be in place and located in a visible or easily accessed area. In cases where there is reasonable cause to believe specific emergencies may arise that will affect vaccine storage, these urgent procedures should be implemented in advance. One easy to implement measure is a 24-hour monitoring and alarmed refrigerator/freezer with a reliable backup power supply. A more sustainable solution should also include establishing an alternative storage facility, with a concrete plan for transporting the vaccine to the second site while maintaining the required cold storage conditions. Insulated containers are a great way to transport vaccines, which we will cover further below.

Vaccine transport & handling

The cold chain must be maintained when transporting vaccines, with the temperature monitored and recorded immediately before and after transport. The use of appropriate containers is vital in this process, with insulated containers being the optimal choice. When preparing the vaccines for transport, refrigerated vaccines should be packed first, with frozen vaccines being packed last, and in separate insulated containers.

An insulated container is a solid-walled container with a tight lid. The required temperature inside the container is maintained through the use of ice or gel packs. Never use bagged or loose ice to transport vaccines. Most insulated containers can maintain a consistent temperature for a maximum of 3-4 hours. If longer transport times are required, the ice packs should be removed and replaced with a new set. Where possible, the temperature of the insulated container should continue to be monitored during transport. When transporting frozen vaccines, the use of dry ice is recommended over insulated containers.

Certain precautions should also be taken when removing the vaccine from cold storage and preparing it for administration. The vaccine should only be removed once it is ready to be administered and should always be protected from light if possible. For multi-dose vaccines, return the unused vaccine to the refrigerator immediately after the required dose has been drawn. Use a label to mark the date and time when the first dose was drawn. Ensure opened vials are fully used within the manufacturer-indicated timeframe.

LabTAG by GA International is a leading manufacturer of high-performance specialty labels and a supplier of identification solutions used in research and medical labs as well as healthcare institutions.