Vaccine carriers protect vaccine potency during immunization sessions and transport to outreach sites. This guidance document is intended to help inform which type of vaccine carrier to select based on local context, to maintain vaccine quality, especially at service delivery points. All freeze-preventive vaccine carriers have a barrier separating the vaccine storage compartment from the frozen water packs, to prevent direct contact. A key advantage of using freeze-preventive vaccine carriers is that at the start of the session day, frozen water packs can be taken directly from the freezer and placed in the vaccine carrier, without conditioning, therefore saving on preparation time while preventing the risk of freezing vaccines.
This is an update to a document published on 21 April 2021 and available at https://apps.who.int/iris/handle/10665/341700. The changes on this guidance were based on the WHO, UNICEF and PATH discussions on the results of the study on the operational use of the freeze-preventive vaccine carrier conducted by PATH. The current version of all WHO information products and publications is authoritative.