麻豆社

To make the coldchain work, it's not just about buying more fridges to keep the vaccines at low enough temperatures - it's figuring out how to power them in countries where there isn't a reliable mains electricity supply. David Elliot is the senior technical consultant at Dulas, which has been developing solar powered fridges for use in rural sub-Saharan Africa. He outlines how trials have worked there, the technology required to deliver vaccines and the challenges, from transportation to training up healthcare personnel.

Photo: A nurse takes some malaria vaccines from the fridge at on Cape Coast, Ghana Credit: Getty Images