Before revision:  The CovidSens concept is motivated by two recent observations: 1) people have been actively sharing their state of health and experience of the COVID-19 via online social media, and 2) official warning channels and news agencies are relatively slower than people reporting their observations and experiences about COVID-19 on social media . We anticipate an unprecedented opportunity to leverage the posts generated by the social media users to build a real-time  analytic system for gathering and circulating vital information of the COVID-19 propagation  . Specifically, the vision of CovidSens attempts to answer the questions of: how to track the spread of the COVID-19?
After revision:  The CovidSens concept is motivated by two recent observations: 1) people have been actively sharing their state of health and experience of the COVID-19 via online social media, and 2) official warning channels and news agencies are relatively slower than people reporting their observations and experiences about COVID-19 on social media , and 3) online users are frequently equipped with substantially capable mobile devices that can perform data processing and analytics. We envision unprecedented opportunity to leverage the posts generated by the social media users to build a real-time analytic system for gathering and circulating vital information of the COVID-19 propagation . Specifically, the vision of CovidSens attempts to answer the questions of: how to track the spread of the COVID-19?