Challenges of improving access to healthcare in developing countries - it's a conversation we need to have. With the help of Dr Jerome Kim, Director General of the International Vaccine Institute, we discuss vaccination and immunization programs as a key aspect of public health and global development – especially in developing nations, where access to life-saving medicines is often limited or non-existent. Karen Heichman, Deputy Director of Diagnostics, Bill and Melinda Gates Foundation, takes us on a journey of the critical role of diagnostics in the fight against diseases.