The COVID-19 vaccines will not end the pandemic if they stay in freezers. In many countries, such as France, COVID-19 vaccines hesitancy is high. It is crucial that governments make it as easy as possible for people who want to be vaccinated to do so, but also that they devise communication strategies to address the concerns of vaccine hesitant individuals. We introduce and test on 701 French participants a novel messaging strategy: a chatbot that answers people’s questions about COVID-19 vaccines. We find that interacting with this chatbot for a few minutes significantly increases people’s intentions to get vaccinated (ß = 0.12) and has a positive impact on their attitudes towards COVID-19 vaccination (ß = 0.23). Our results suggest that a properly scripted and regularly updated chatbot could offer a powerful resource to help fight hesitancy towards COVID-19 vaccines.