Online discussions of science involve complex interactions among experts, news media, and social media users as they interpret and disseminate scientific findings. While prior work has examined these actors in isolation, their interplay in shaping science communication remains poorly understood. Using the COVID-19 pandemic as a case study, we analyze 1.24M tweets and 211k news articles that reference pandemic-related scientific papers. We find that the most influential Twitter accounts in this discourse are predominantly individuals with medical or research credentials. However, we also identify a coordinated network that disproportionately amplifies a small set of prominent credentialed experts who advance contrarian, anti-consensus positions on vaccines, lockdowns, and related topics. The papers promoted by these influential actors substantially overlap with those covered by news media, but with key differences: pro-consensus experts primarily engage with studies featured by mainstream and medical outlets, whereas contrarian experts align more closely with papers promoted by low-quality, pseudoscientific, or conspiratorial sources. Notably, news outlets tend to report on scientific studies after they have been highlighted by social media superspreaders. Together, these findings reveal multi-level pathways of information flow and coordinated amplification structures that shape science communication across social media and news, offering new insights into the dynamics of the broader information ecosystem.

翻译：在线科学讨论涉及专家、新闻媒体和社交媒体用户在解释和传播科学发现时的复杂互动。尽管先前的研究已孤立审视这些主体，但它们在塑造科学传播中的相互作用仍不清楚。以COVID-19大流行为案例，我们分析了124万条推文和21.1万篇提及大流行相关科学论文的新闻文章。研究发现，在这一话语中最具影响力的推特账户主要是持有医学或研究资质的个人。然而，我们还发现了一个协调网络，该网络过度放大了少数几位知名持证专家的声音，他们在疫苗、封锁及相关议题上提出反共识的对立观点。这些有影响力主体推广的论文与新闻媒体覆盖的论文有大量重叠，但存在关键差异：支持共识的专家主要涉及主流和医学媒体报道的研究，而持对立观点的专家所推广的论文则更多与低质量、伪科学或阴谋论来源的内容相符。值得注意的是，新闻媒体往往在社交媒体超级传播者突出报道某科学论文之后，才开始对其进行报道。综上，这些发现揭示了跨越社交媒体和新闻的科学传播中多层次的信息流路径与协调放大的结构，为理解更广泛信息生态系统的动态提供了新见解。