Table 5.

Keywords of the five topics with emotion of fear.

Topic	Keywords
1	Virus, COVID-19, outbreak, infection, mutation, transmission, omicron, human, vaccine
2	Case, confirmed, new, infected, asymptomatic, month, day, native, foreign, imported
3	Cases, confirmed, new, COVID-19, vaccination, million, vaccine, cumulative, death, Korea, infection
4	Positive, infected, test, nucleic acid, found, personnel, control, virus, COVID-19, case, isolation
5	Case, outbreak, personnel, prevention and control, Tibet, age, asymptomatic, Yazhou District, nucleic acid