To maintain the quality of vaccines throughout the delivery process, they must be stored in the 2-8 degrees Celsius range. Yet, an estimated 75% of vaccines are exposed to harmful temperatures by the time they make it through the supply chain, increasing the likelihood of being ineffective upon delivery. Our focus is to strengthen the vaccine supply chain by identifying the weakest points and customizing improved routes for more efficient and equitable distribution of vaccines—ultimately bringing rates of exposure to harmful temperatures down to zero.