Cold chains are likely to play a significant role in the delivery of a COVID-19 vaccine. To reach herd immunity (defined as the indirect protection of individuals from an infectious disease when a high proportion of the population is immune) it is estimated that between 60 and 70 percent of the population will need to obtain immunity either through a vaccination or the development of antibodies following an infection. As the world manages the necessary and urgent expansion of these cold chains, we must ensure the investment relies on sustainable solutions and delivers a lasting legacy.