Immunisation is one of humankind's greatest health success stories. It averts two to three million deaths a year. In 2015, about 86 percent of kids worldwide received three doses of the diphtheria-tetanus-pertussis vaccine, protecting them from disability or an untimely death. The World Health Organisation estimates that an additional 1.5 million deaths could be avoided every year if global vaccination coverage was improved. That's tricky, because many vaccines require a constant temperature to stay effective. Broadway’s hi-tech, rechargeable cooling system was inspired by an invention developed by Albert Einstein in the 1920s. The device was originally intended to provide electricity-free refrigeration, and required only a heat source to drive a chemical process. The Isobar is specifically designed to maintain stable temperature control between 2C (35F) and 8C (46.4F) during the “final mile” distribution of vaccine in remote regions without power.