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Safeguarding Viability and Efficacy of COVID-19 Vaccines: Key Considerations

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While getting vaccinated against COVID-19 is not a guarantee that one will not get infected or re-infected by the virus, it is definitely among the most effective ways to forestall the pandemic. COVID-19 vaccines bolster the immunity of vaccinated individuals and when conducted en masse it helps to provide herd immunity. Consequently, vaccine development and deployment is a top priority for most governments at this point.1,2

Unfortunately, manufacturers and suppliers of COVID-19 vaccines face numerous challenges in the distribution of these vaccines. The vaccines are very sensitive to fluctuations in internal conditions and could easily lose their viability and efficacy if their storage conditions are not ideal.3,4,5 If success is to be achieved with the global COVID-19 vaccination efforts, all staff involved should be trained on maintenance of the cold chain supply, freezer operations, and vaccine handling to protect the integrity of vaccines.

Management of Different COVID-19 Vaccines

1.  Pfizer BioNTech COVID-19 Vaccine

This vaccine has a maximum shelf life of about 6 months when stored in a freezer at -80 °C to -60 °C. Once removed from the freezer it should be kept at a temperature of 2 to 25 °C for a period of 2 hours before it is diluted. Once diluted it can be stored for a maximum of 6 hours at a temperature that does not exceed 25 °C. During storage, you should minimize exposing the vaccine to too much light or ultraviolet rays. Do not attempt to refreeze the vaccine once it has been thawed.6

2.  AstraZeneca COVID-19 Vaccine

This vaccine has a maximum shelf life of 6 months if it is refrigerated at temperatures between 2 to 8 °C. This vaccine must not be frozen and during refrigeration, it should be stored away from direct light. Once removed from the fridge it can keep for an additional 6 hours at temperatures of 2 to 25 °C.6

3.  Moderna COVID-19 Vaccine

This vaccine has a maximum shelf life of 7 months if stored in a freezer in the temperature range of -25 °C to -15 °C. It should never be stored in extreme temperatures below -40 ºC. Once removed from the freezer, it should be assigned immediately and can keep for up to 12 hours at temperatures of 8 to 25 °C. However, the vaccine must be used within 6 hours if the vial has already been punctured. Keep away from direct sunlight.6

Storage of COVID-19 Vaccines

All freezer storage units that store COVID-19 vaccines must have temperature stabilizers to maintain the temperatures at the recommended temperature range. The temperature must always be confirmed prior to placing the vaccine into the freezer unit. The internal temperature should range between -80 oC to -60 oC for most vaccines. However, the Moderna COVID-19 vaccine requires an internal temperature of -25 oC to -15 oC with a recommended storage temperature of -20 oC.7

The temperature of the freezer unit needs to be checked and recorded in a temperature log. Regular inspection needs to be conducted by a certified company and records should be maintained as they may be randomly requested during audits.7


  • Once COVID-19 vaccines are received at a facility, the receiving time should be documented as well as the minimum and maximum temperatures of the vehicle storage units.
  • The storage temperatures should then be recorded at the beginning and end of each business day. Digital data loggers can be used to automatically monitor the temperature of the specialized storage units. They have specifications for downloading and replacement which should be specified by the manufacturer.
  • Every time the storage unit is accessed, the temperature should be checked and an alarm raised in case there are any major fluctuations.

Vaccine Transportation – Cold Chain

The Food and Drug Administration (FDA) has stringent rules on maintaining the cold chain during the transportation of COVID-19 vaccines.

1.  Temperature Control

The temperature of the vaccines needs to be maintained strictly during transportation regardless of whether they are being transported off-site or on-site. This should be maintained in accordance with the set standards for storage temperatures as well as timings. Should the storage container be opened in transit, the temperature should be rechecked. Hence, it is important to monitor temperature at all times.8

2.  Labeling

During the transportation of COVID-19 vaccines, all storage containers should be accurately labeled. Vials and re-drawn syringes should also be accurately labeled to prevent mix-ups.

3.  Supplies

  • Before the shipment, ensure that you have all the required supplies loaded in the transportation vehicle. Have extra coolant materials, temperature monitors, and insulators.
  • Check doors throughout the shipment to ensure that they remain tightly closed to prevent temperature fluctuations.
  • Have a contingency plan in place in case of power outages or malfunctions of the storage units. It is necessary to have an emergency power supply.
  • Have extra storage space for the vaccines.
  • Have data loggers to monitor storage temperatures continuously. The batteries should be changed at least annually and an alarm system needs to be in place in case there is a major temperature fluctuation.8

Figure 1: A schematic representation to depict how to safeguard efficacy and viability of COVID-19 vaccines (Figure courtesy of CLOUDLIMS)

Importance of Biobanks in Maintaining the Integrity of COVID-19 Vaccines

Biobanks have expertise
in handling ultra-low temperature freezers and managing cold chains and can play a crucial role in supporting COVID-19 vaccine distribution programs across the globe. Biobank managers are tasked with the responsibility of ensuring high standards of quality in safeguarding the viability and efficacy of COVID-19 vaccines and training the biobank’s staff on the correct protocol of handling vaccines. Furthermore, biobanks can play an important role in training new users in the vaccine supply chain and educating them to follow best practices for the storage and transport of vaccines.

Biobanks can leverage an integrated software that can unify all
clinical and biological information associated with COVID-19 vaccines. A fully integrated biobanking LIMS (Laboratory Information Management System), that includes a freezer inventory management software solution, can serve as a repository for this information.

An interoperable freezer inventory software solution can track all the variables, such as temperature, that are necessary for ensuring the viability and efficacy of the vaccines. It also helps manage vaccine locations, maintain a chain of custody, manage recipient demographics and billing, monitor compliance and security. A freezer inventory management software can be integrated with temperature monitoring devices to continuously monitor and record storage temperatures to enable the preservation of the cold chain system. Should there be major fluctuations, a freezer inventory management software triggers an alarm and notifies the biobanking staff before the freezer temperature changes significantly.

Figure 2: Freezer inventory management software to mirror storage inventory of biobanks and to easily locate COVID-19 vaccines stored in freezers (Figure courtesy of CloudLIMS

Larger centralized biobanks play a key role in ensuring successful COVID-19 vaccine storage to avoid catastrophic vaccine loss and compromising patient safety.


To safeguard the viability and efficacy of COVID-19 vaccines, a number of parameters have to be in place. Of great importance is the need to maintain temperatures within the acceptable range. Cold chain management when transporting the vaccines must be prioritized and adequate measures put in place. Biobanks play a vital role in vaccine supply chain readiness by ensuring effective storage and safe distribution of COVID-19 vaccines. A fully automated freezer inventory management software in a biobanking LIMS tracks all the variables and manages them to maintain the integrity of the COVD-19 vaccines throughout the entire lifecycle.

About the author:

Shonali Paul is chief operating officer for CloudLIMS. In a career spanning over twenty years, Shonali has built a long and impressive track record of success in high technology bioinformatics workflow solutions, strategic collaborations, developing operational strategy and directing new business initiatives from conception through execution.

She has helped build the offshore development center in India and is the key driver of the development, operations and product teams. She has been the key person responsible for corporate acquisitions. She has been extensively published in journals such as BIO, Lab Manager, Technology Networks and has given talks at conferences of ISBER, ESBB, Labroots. She has been a member of the marketing committee and the IT working group, a global biobanking organization. She is now the chair of the Member Relations Committee at ISBER.


1. Lurie N, Sharfstein JM, Goodman JL.  The Development of COVID-19 Vaccines; Safeguards Needed. JAMA. 2020;324(5):439-440. doi: 10.1001/jama.2020.12461

2. Global, Equitable Distribution of Safe COVID-19 Vaccines Is Imperative. Clinical Lab Manager. https://www.clinicallabmanager.com/news/covid-19-vaccination-potential-will-not-be-achieved-without-increased-production-affordable-pricing-global-availability-and-successful-rollout-25134. Published February 16, 2021. Accessed June 1, 2021. 

3. Four Keys to Successful Vaccine Storage. Clinical Lab Manager. https://www.clinicallabmanager.com/technology/four-keys-to-successful-vaccine-storage-25020. February 8, 2021. Accessed May 28, 2021.

4. Vaccine Storage and Handling. Centers for Disease Control and Prevention. https://www.cdc.gov/vaccines/hcp/admin/storage-handling.html. Accessed May 28, 2021.

5. COVID-19: Vaccine Storage and Handling Guidance. Ministry of Health. Canada. https://www.health.gov.on.ca/en/pro/programs/publichealth/coronavirus/docs/vaccine/vaccine_storage_handling_pfizer_moderna.pdf. Version 5.0 – June 8, 2021. Accessed June 9, 2021.

6. Transporting, storing and handling COVID-19 vaccines. Australian Government Department of Health and Aged Care. https://www.health.gov.au/initiatives-and-programs/covid-19-vaccines/advice-for-providers/clinical-guidance/transporting-storing-and-handling  Last updated September 1, 2022. Accessed September 20, 2022.

7. Ultra low temperature freezers: Key considerations for COVID-19 vaccines. International Society for Biological and Environmental Repositories (ISBER). https://cdn.ymaws.com/www.isber.org/resource/resmgr/covid_19_vaccinations/bp-coldchain_v06_1.11.2020.pdf. Accessed May 28, 2021.

8. COVID-19 Vaccine Handling Toolkit. Transporting COVID-19 Vaccines Off-Site. USP.org. https://www.usp.org/covid-19/vaccine-handling-toolkit. Last Updated May 11, 2021. Accessed May 28, 2021.