This report outlines the current state of COVID-19 vaccine hesitancy (defined as preferring to delay vaccination) and resistance (defined as not wanting to take the vaccine at any point), as well as the results from two experiments designed to test strategies for increasing Americans’ willingness to take the vaccine when it’s available to them. We evaluate the results of two experiments testing different communication strategies to increase people’s willingness to take the COVID-19 vaccine. Key findings are that a variety of messages are effective for reducing vaccine hesitancy and resistance, while messengers are less effective and − in the case of partisan messengers − have the potential to increase resistance among political out-groups. The most effective strategies evoked scientists and people’s own doctors as endorsers of vaccination. We found, also, that messages evoking harm reduction and “people you know” were more effective in counties where the virus is spreading more quickly.