I. Introduction
The pandemic evolution has been previously tracked and projected using the statistic report (e.g., confirmed and death cases). Despite the significant technological leaps in pandemic surveillance, the very recent COVID-19 evidently showed the vulnerabilities of our modern society in response to the emerging pandemic. To complement the traditional indicator-based surveillance through government reports, online resources through AI techniques showed its advantages in early detection and further forecasting of emerging pandemics. For example, the peak of search volume on COVID-19 pandemic was 20 days earlier than the issuance of official warnings [1]. Online platforms provide rich information to anticipate and explain the course of outbreaks while also reflecting public knowledge and perceptions when used in a timely manner to assist official surveillance. Fig.1 illustrates our motivation examples, which show different stances of web users on the COVID-19 pandemic and the government regulations.