COVID-19 represents the most severe global crisis to date whose public conversation can be studied in real time. To do so, we use a data set of over 350 million tweets and retweets posted by over 26 million English speaking Twitter users from January 13 to June 7, 2020. In characterizing the complex retweet network, we identify several stable communities, and are able to link them to scientific expert groups, national elites, and political actors. We find that scientific expert communities received a disproportionate amount of attention early on during the pandemic, and were leading the discussion at the time. However, as the pandemic unfolded, the attention shifted towards both national elites and political actors, paralleled by the introduction of country-specific containment measures and the growing politicization of the debate. Scientific experts remained present in the discussion, but experienced less reach and a higher degree of segregation and isolation. Overall, the emerging communities are characterized by an increased self-amplification and polarization. This makes it generally harder for information from international health organizations or authorities to reach a broad audience. These results may have implications for information dissemination in future global crises.

中文翻译：

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在 COVID-19 大流行期间，Twitter 上的国际专家社区变得更加孤立

COVID-19 是迄今为止最严重的全球危机，可以实时研究其公开对话。为此，我们使用了 2020 年 1 月 13 日至 6 月 7 日期间超过 2600 万英语 Twitter 用户发布的超过 3.5 亿条推文和转发的数据集。在表征复杂的转发网络时，我们确定了几个稳定的社区，并且能够将他们与科学专家组、国家精英和政治行动者联系起来。我们发现，在大流行的早期，科学专家社区受到了不成比例的关注，并在当时引领了讨论。然而，随着大流行的展开，注意力转移到国家精英和政治行为者身上，与此同时，针对特定国家的遏制措施的出台和辩论的日益政治化。科学专家仍在讨论中，但他们的影响范围更小，隔离和隔离的程度更高。总体而言，新兴社区的特点是自我放大和两极分化。这使得来自国际卫生组织或当局的信息通常更难到达广泛的受众。这些结果可能对未来全球危机中的信息传播产生影响。