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Middlesex-London Health Unit

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Cold Chain

Public Health Nurses and Public Health Inspectors in Middlesex-London check vaccine fridges once a year to confirm that health care providers are following provincial guidelines for storing vaccine.


What is Cold Chain?

Cold chain is the process of storing vaccines properly during delivery, handling, and storage in refrigerators. If the temperature is not maintained between +2°C and +8°C, vaccine effectiveness may be decreased. The vaccine may not look like it had an exposure outside of the required temperature range, but the person who receives it may not get proper protection.

vials of vaccine

The Province of Ontario mandates the program through the Vaccine and Storage Handling Protocol. Health care providers order publicly funded vaccine from their local health unit and health unit staff check locations where the vaccine is stored. Inspections happen at least once yearly in all locations (doctor’s offices, walk-in clinics, hospitals, long-term care homes and pharmacies).

If you have questions about which vaccines to order, vaccine scheduling or cold chain recommendations, you can speak with a public health professional at 519-663-5317 ext. 2330.

What is a cold chain incident?

An “incident” or “failure” happens when the fridge temperature where the vaccine is being stored goes below +2°C or above +8°C. When this happens, the health care provider needs to call the health unit right away.

Public health unit staff will assess the situation and let you know which vaccines can still be used. 

How do I report a cold chain incident?

  • Call the health unit right away 519-663-5317 ext.2330  to discuss the incident
  • Record the vaccines involved in the incident  on the Cold Chain Incident Form (PDF) Also note if any multi-dose vials have already been opened
  • Be prepared to fax in your fridge temperature logs
  • Place all of the vaccine involved in the incident into a bag labeled “do not use until assessed”, keep the bag inside of a monitored refrigerator that is at the right temperature
  • Do not use any of the vaccine until the incident is assessed by the health unit
  • If anyone was immunized with this vaccine during the cold chain incident, keep track of their information in case follow-up is required
  • New vaccine cannot be ordered until the refrigerator  is maintaining the proper temperature range again, or the problem is resolved

Taking care of vaccine (PDF 254KB)

Each office should have a designated staff member that is responsible for the vaccine. They can ensure that the temperature is monitored twice daily and recorded, be in charge of ordering, and following protocols if there is an issue with maintaining the cold chain. Make sure that everyone in the office is aware of recommended vaccine handling and storage procedures in case the main staff member is away from work.

Date of creation: February 27, 2013
Last modified on: August 20, 2019

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1Public Health Agency of Canada, Vaccine handling guidelines Retrieved from