George Marcus’s methodology for multi-sited ethnography is widely discussed and applied in anthropology and the strategy of ‘following the conflict’ has been a fruitful approach to studying controversies and conflicts. Drawing on my shifting methodology in the initial stages of a digital ethnography project on vaccination-related online community forums, I explore ‘the war’ on vaccines using a broadened strategy that includes following agreements and silences within the controversy. By examining the debate in conjunction with medical anthropology research, I discuss how both vaccine-cautious and vaccine-confident forum members challenge conventional debate divisions, such as scientific–unscientific, evidential–anecdotal and genetic–environmental, while still adhering to medico-scientific discourses as zones of agreement. Whereas an agreement-oriented methodology contributes to research on liminal zones and reconfigured forms of bio-citizenship and literacy, the strategy of ‘following silences’ highlights the limits to liminality in a debate underpinned by adultism that silences the views of young people.