The Spread of Anti-vaccination Memes on Facebook

False claims about vaccines can find large audiences online, leading to vaccine hesitancy. The most influential content on social media is often visual, but studies about misinformation largely focus on text instead of images. This study uses newimage analysis capabilities that Facebook and Instagram have made available to understand the spread of visual anti-vaccinationmemes on these platforms. We identified 200 influential memes that contain scepticism or hesitancy towards vaccines and the 15,000 public Facebook accounts on which the memes have been shared. We describe the memes' spread on a large scale by identifying communities of accounts and describing the diffusion pathways of memes between the communities. We develop a novel method of testing whether a meme has spread from one community of accounts to another that works on sequential time series alone. We identify 16 distinct communities of Facebook accounts and categories them based on thematic and regional focus. Anti-vaccination memes originate predominantly from North American Facebook accounts. These accounts often focus on opposing COVID-19 policies or promoting conspiracy theories about elites. Memes from these communities also spread internationally, particularly to Europe, demonstrating their influence beyond North America. The analysis demonstrates that memes receive the most engagement within their initial community. However, their overall reach depends on their ability to spread to other communities. This suggests that the ability of memes to find large audiences is based on their capacity to spread beyond their original contexts and to be used by groups with potentially different agendas.