The status of refrigeration techniques for vaccine storage and transportation in low-income settings

Vaccines need to be continuously stored between 2°C to 8°C, from their production to administration to beneficiaries. Every year, more than 25% of vaccines are wasted. One of the main reasons for this wastage is the lack of cold chain continuity in low-income settings, where electricity is scarce. Recently, several advances have been made in cooling technologies to store and transport vaccines. The current paper presents a review of refrigeration technologies based on scientific publications, industry white papers and other grey literature. For each refrigeration method, we describe its working principle, the best performing devices available as well as the remaining research challenges in order to obtain a very high degree of performance enhancement. Finally, we comment on their applicability for vaccine transport and storage.