Many<unk> s require refrigeration to remain active, and the lack of infrastructure to maintain the cool chain to reliably bring<unk> s into more remote areas of developing countries poses a serious challenge to national immunization programs. Post millennium, a portable<unk>  unit has been proposed by several technologists. The WHO Performance, Quality and Safety (PQS) programme is a driver of the technology. __TOC__
Vaccine cooler
Vaccine storage
Animal vaccination
Water for injection
Vaccine vial monitor
Timeline of human vaccines
Vaccine ingredients
Isolation tank