Storing COVID-19 vaccines in the fridge: best practice

John Minshull, Deputy Director, London Medicines Information Service, Specialist Pharmacy ServicePublished Last updated See all updates

Correct storage of the vaccine ensures its efficacy. Minor fluctuations can be managed in limited cases.

Key points

Correct storage of COVID-19 vaccines ensures their efficacy. There is a risk that a vaccine may be rendered ineffective if it is not stored correctly. Effective cold chain management of a vaccine is always important and is key to ensure success of a national vaccination programme.


This page has been written to support organisations in preventing avoidable deviations in refrigerated storage temperature. These are general principles for good practice for the storage of vaccines. Each vaccine will have its individual licensing requirements, which must also be considered.

The Green Book (Chapter 3) and the PHE Vaccine Incident Guidance states that all immunisation providers should have a named individual responsible for vaccine storage and that there are policies, protocols and procedures for the maintenance of the vaccine cold chain. We recommend that at their simplest they must include:

  • How to set up a new fridge, including temperature range
  • How to routinely maintain and monitor the fridge
  • Maintaining the cold chain during transportation
  • How to handle any incidents that occur

They should include detailed written emergency vaccine storage and handling plans which cover the actions to take in the event of out of range temperature excursions or refrigerator break down.

Setting up, maintaining and monitoring a fridge

Information on setting up, maintaining and monitoring a fridge can be obtained from:

Using a “load probe” to increase accuracy

We recommend that in addition to monitoring the air temperature of the fridge, a temperature probe should be placed into “mock up” product close to the stored vaccines. This is known as a “load probe”. This probe will more accurately represent the effect of temperature fluctuations on the temperature of the vaccine itself.

The temperature probe in the air may register transient out of limit temperatures during normal opening and closing of the door, so the load probe thermometer can be used to give assurance that the vaccine itself has remained within range at all times. The load probe can also be useful in investigating the effects of a fridge failure.

Maintaining the cold chain during transportation

Advice on the use of cool boxes for transport can be found in:

The cool life of cool boxes varies between manufacturers, and is affected by how the box is used, so local evaluation of suitability will be needed. If frozen cool packs are to be used take care to ensure the vaccine cannot become frozen during transport.

Handling incidents

Detailed guidance on handling incidents can be found in The Green Book (Chapter 3) and PHE Vaccine Incident Guidance.
In the event of a temperature excursion, always refer to the guidance above and:

  • Make safe: return the vaccine to the correct storage temperature
  • Quarantine: ensure the stock cannot be used until the investigation is complete.
  • Gather information: what happened? How warm did the vaccine become? For how long? Did the vaccine freeze?
  • Decide whether the vaccine may be used.

Getting further advice following fluctuations in temperature

It is a local clinical decision to use any vaccine which has been stored outside of the recommended temperature. This decision should be based upon information gathered regarding the temperature excursion and any additional advice required.

For further information contact your Regional QA Specialist. For advice following a temperature excursion contact your local Regional Vaccinations Operations Centre and your Regional Chief Pharmacist.

Change history

  1. Amendment to who to contact under "Getting further advice following fluctuations in temperature" section

  2. Added key points section; examples of what to include in cold chain policies/procedures; information about setting up a fridge; "load probe" information; maintaining cold chain during transportation; handling incidents.

  3. Published