Storing COVID-19 vaccines in the fridge: best practice

John Minshull, Deputy Director, London Medicines Information Service, Specialist Pharmacy ServicePublished

Correct storage of the vaccine in the fridge following its removal from the freezer ensures its efficacy. Minor fluctuations can be managed in limited cases.


This page has been written to support organisations in preventing avoidable deviations in refrigerated storage temperature. Improper vaccine storage is a significant concern for any national immunisation programme. Queries often arise about what to do when vaccines have been exposed to temperatures outside of the recommended range. 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.

PHE Vaccine Incident Guidance states that all immunisation providers should have policies, protocols and procedures for the maintenance of the vaccine cold chain. These 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.

Avoiding temperature excursions is therefore the best plan, particularly since:

  • vaccines are in short supply;
  • there is limited evidence available with which to make recommendations about use vaccines following a deviation.

Managing minor excursions

Whilst avoiding excursions is the best policy, managing minor excursions can be achieved in the limited circumstances described below. 

Best practice to avoid cold storage issues

National guidance

We have followed advice in The Green Book (Chapter 3) and PHE Vaccine Incident Guidance to create two infographics to support best practice in order to avoid cold storage issues:

  • Refrigerators for COVID-19 vaccine storage – Quick Reference Guide
  • Cool Box Quick Reference Guide: Pfizer-BioNTech COVID-19 Vaccine

Advice on temperature monitoring

We recommend that monitoring the temperature of the refrigerated load better represents the actual effect of temperature fluctuations on the vaccine and therefore better informs decisions about temperature deviations.

  • The load temperature fluctuates less than air temperature;
  • A load thermometer can be purchased or can be achieved by placing a temperature probe into a similar “mock up” product, placed within the middle of the stored vaccines;
  • Measuring air temperature shows rapid changes in the refrigerator temperature. In a busy clinical environment where the refrigerator door is opened often, this will result in an alarm and create concern that vaccine integrity has been compromised.

Vaccines are medicinal products. A pharmaceutical refrigerator is required for the storage of refrigerated medicinal products. The air within this type of refrigerator is circulated by a fan, which provides a uniform temperature profile and a rapid temperature pull down after the door has been opened.

Dealing with minor fluctuations in temperature

Gathering information

The Green Book (chapter 3) (page 30) advises that local protocols should be in place that outline the steps to take and information to gather following a fridge failure or a disruption to the cold chain. Details of what these should include are presented in the Green Book.

Taking action

PHE Vaccine Incident Guidance is clear: the significance of any breach in the cold chain is a function of the length of time the product is outside the recommended conditions, and the temperature it was exposed to. The guidance suggests that each breach of the cold chain must immediately be acted on and a decision made about what actions, if any, are required.

Getting further advice following fluctuations in temperature

It is a local clinical decision to use any vaccines 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 advice on temperature fluctuations get in touch with us or your local Regional Vaccinations Operations Centre (your Regional Chief Pharmacist will have these contact details).