The reappearance of measles in the US and Europe, a disease considered eliminated in early 2000s, has been accompanied by a growing debate on the merits of vaccination on social media. In this study we examine the extent to which the vaccination debate on Twitter is conductive to potential outreach to the vaccination hesitant. We focus on Italy, one of the countries most affected by the latest measles outbreaks. We discover that the vaccination skeptics, as well as the advocates, reside in their own distinct "echo chambers". The structure of these communities differs as well, with skeptics arranged in a tightly connected cluster, and advocates organizing themselves around few authoritative hubs. At the center of these echo chambers we find the ardent supporters, for which we build highly accurate network- and content-based classifiers (attaining 95% cross-validated accuracy). Insights of this study provide several avenues for potential future interventions, including network-guided targeting, accounting for the political context, and monitoring of alternative sources of information.

中文翻译：

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落入回声室：推特上的意大利疫苗接种辩论

麻疹在美国和欧洲再次出现，这种疾病在 2000 年代初被认为已被消灭，与此同时，社交媒体上关于疫苗接种优点的争论也越来越激烈。在这项研究中，我们检查了 Twitter 上的疫苗接种辩论在多大程度上有助于对疫苗接种犹豫不决的潜在外展活动。我们关注意大利，这是受最新麻疹疫情影响最严重的国家之一。我们发现疫苗接种怀疑论者和拥护者都居住在他们自己独特的“回声室”中。这些社区的结构也各不相同，怀疑论者被安排在一个紧密相连的集群中，而倡导者则围绕几个权威中心组织起来。在这些回声室的中心，我们找到了热心的支持者，为此，我们构建了高度准确的基于网络和内容的分类器（达到 95% 的交叉验证准确度）。这项研究的见解为未来潜在的干预措施提供了多种途径，包括网络引导定位、政治背景说明和替代信息来源的监控。