Preventing Freezing of Vaccines Through a New Class of Passive Cold Chain Equipment

Nancy Muller from PATH in the U.S. will develop approaches to prevent freezing and thereby destruction of vaccines during cold chain transport. Maintaining vaccines below 8°C while preventing freezing is particularly challenging during their transport in developing countries. In Phase I they designed low-cost liners containing engineered phase change materials that fit existing vaccine carriers and provide a thermal buffer between the vaccines and standard ice-packs. The liners were tested using a new experimental freeze-test protocol, and met WHO performance, quality and safety functional requirements. Connections with vaccine carrier manufacturers were also established to promote the development of compatible vaccine carriers, and one prototype was field-tested in Vietnam for efficacy and ease of use. In Phase II, Pat Lennon, also from PATH in the U.S. will assist cold chain equipment manufacturers and the WHO in product design, testing, and generating demand, to help bring freeze prevention methods for vaccine transport into the market.