Public Opinion Propagation and Evolution of Public Health Emergencies in Social Media Era: A Case Study of 2018 Vaccine Event

[Objective] This paper tries to investigate the rules of public opinion propagation and evolution of public health emergencies and propose corresponding policies in the context of social media era. [Methods] Based on ELM, TAM and life cycle theory, the influencing factor model was established to explore the impact of information publishers, information content and information release time on public opinion propagation of public health emergencies. [Results] The empirical analysis showed that the right to discourse is mastered by different interest groups in different periods of public opinion development. Information with great timeliness and novelty spreads more widely. If official media show some subjectivity, the retweet volume of their tweets will be larger. [Limitations] Only one case was empirically analyzed and the compatibility of the model needs to be improved. [Conclusions] The model that comprehensively considers identity of information source, quality of information content and life cycle is a good way to explain the public opinion propagation and evolution rules of public health emergencies on social media platforms. © 2019 Authors. All rights reserved.