Aide-mémoire for prevention of freeze damage to vaccines

Cold chain storage is necessary to prevent damage to vaccine due to heat exposure, but keeping vaccines too cold can be just as harmful as keeping them too warm - many vaccines are damaged by freezing. WHO guidelines recommend that many liquid vaccines should not be frozen. Freezing of these vaccines results in loss of potency which can never be restored. Use of the vaccine can result in decreased effectiveness in recipients. This aide-memoire summarizes WHO guidance on prevention of vaccine freezing in a concise 2-page document that can be used as a reminder of previously published material and is ideally suited as a communications tool, job-aid or learning resource.