A guide to the proper storage of vaccines

05 November 2024

The crucial importance of proper vaccine storage

Vaccines, being sensitive biological products, require storage at strictly controlled temperatures to ensure their efficacy and safety. Incorrect temperatures, whether too high or too low, can alter their composition and compromise their ability to stimulate an effective immune response, putting vaccinated individuals at increased risk of infection.

In addition, improper storage can cause changes in the vaccines, increasing the risk of adverse reactions such as temperature, pain at the injection site or allergic reactions, causing risks for the health of patients.

Maintaining the correct temperature during all stages of the cold chain, from storage to administration, is therefore crucial to ensure maximum protection against infectious diseases. For this reason, it is essential to follow the international guidelines for vaccine storage, developed by the World Health Organisation (WHO), which provide detailed recommendations on all aspects of the cold chain, from storage temperatures to transport procedures.

Storage of COVID-19 and influenza vaccines: correct temperatures and conditions

Vaccine storage conditions vary according to the type of vaccine and affect the entire cold chain from storage to administration.

Inactivated influenza vaccines: require temperature-controlled storage between +2°C and +8°C.
MMR (measles, mumps, rubella) vaccines: can be stored at slightly lower temperatures down to 0°C.
COVID-19 vaccines: initially required very strict storage conditions at very low temperatures (-70°C or -80°C), which was a major logistical challenge. However, the storage conditions for some COVID-19 vaccines have been updated to be less restrictive. For example, the Pfizer-BioNTech vaccine can now be stored at standard freezer temperatures (-25°C to -15°C) for a limited period of time and, once thawed, in a refrigerator (2°C to 8°C) for up to 5 days. These changes have facilitated distribution and administration, making them more accessible in areas with less developed infrastructure.

It is essential to always consult the manufacturer's specifications and updated information from health authorities to know the correct storage temperatures for each vaccine.

Vaccine storage solutions

Proper storage of vaccines requires specific solutions to ensure that recommended temperatures are maintained, preventing damage and ensuring maximum efficacy. Below are some of the main solutions available:

Medical refrigerators: medical refrigerators are specifically designed to ensure optimal vaccine storage, offering precise temperature control, superior thermal uniformity and rapid temperature recovery after opening.
Vaccine freezers: there are different types of vaccine freezers designed to provide a wide range of storage temperatures, from the most common to ultra-low, depending on the specific requirements of each product. For vaccines that require ultra-low storage temperatures (-70°C or -80°C), Ultra-deep freezers for medical applications are the ideal solution, ensuring that these extreme conditions are maintained and the integrity of the most sensitive vaccines is preserved. Other vaccines can be stored in freezers at less stringent temperatures, but still below those of standard medical refrigerators.
Monitoring systems: temperature monitoring systems track storage conditions in real time, send alarms in the event of anomalies and ensure the traceability of vaccines.
Temperature-controlled transport: During transport, it is essential to use portable medical refrigerator-freezers that maintain the correct temperature of the vaccines to avoid interruptions in the cold chain.

Proper vaccine storage practices

In addition to the use of appropriate equipment, a number of good practices are essential to ensure the proper storage of vaccines:

Correct positioning: vaccines must be positioned correctly inside the refrigerator or freezer, avoiding direct contact with the walls and leaving sufficient space for air circulation.
Regular temperature checks: the temperature inside the refrigerator or freezer must be checked regularly, at least twice a day, to ensure that vaccines are stored under the correct conditions.
Preventive maintenance: refrigerators and freezers must undergo regular preventive maintenance to ensure their proper functioning and prevent breakdowns.
Staff training: staff handling vaccines must be adequately trained in storage procedures and what to do in the event of anomalies.

Investment in medical refrigerators and freezers is essential to ensure the proper storage of vaccines and the integrity of the cold chain. Evermed, with its expertise in medical refrigeration, offers state-of-the-art, regulatory compliant solutions.