In this bonus episode, we speak to Prof Heidi Larson, Director of the 'Vaccine Confidence Project'. Heidi and her team have just published a 5 year study looking at public confidence in vaccines worldwide, across 149 countries. She discusses increases and declines in confidence, and what can be done to understand these different views in order to increase confidence and optimise vaccine uptake, which will be crucial with the hopeful arrival of a COVID-19 vaccine.