How does the development of COVID-19 affect the public's engagement to fake news rebuttal microblogs?

COVID-19 infodemics are intertwined with the dynamic development of the pandemic. During infodemics, the challenges and difficulties are to reveal the dynamic evolution of public's engagement to fake news rebuttals information and break through the bottleneck of previous static research. Motivated by this, fake news rebuttals engagement index (FNREI) is proposed to state the public engagement towards COVID-19 related fake news rebuttals. A total of 19,603 fake news rebuttals microblogs from Weibo are divided into four categories by latent dirichlet allocation (LDA): "status and confirmed cases of COVID-19 '', "transmission mode and living conditions of coronavirus", "prevention and detection of COVID-19 '' and "overseas fake news and derivative events". Time-varying parameter vector auto-regressive model (TVP-VAR) is used to explore the time-varying impact of the COVID-19 life cycle and the appearance of virus mutation (Delta, Omicron) on four categories of FNREI time series. The research results suggest that under the impact of different major events during the COVID-19 life cycle, the public's engagement to different categories of COVID-19 related fake news has different priorities, its duration and intensity is dynamically changing. This study explores the evolution of individuals' engagement to fake news rebuttals information during the COVID-19 and provides a basis for improving fake news governance effectiveness.