Table 3.
Subjects drawn from LDA topic modeling in phases 1, 2 and 3.
| Phase 1 | |||
|---|---|---|---|
| Topic Number | Topic | Percentage | Major Keywords |
| 3 | Current status of and information on COVID-19 | 27.6% (1068/3870) |
Today, variants, self-quarantine, confirmed cases, domestic, life |
| 1 | Development of vaccines and cures | 24.5% | Cures, clinical, research, clinical trial, medicine |
| 2 | Economic issues related to vaccines | 20.8% | USA, American stocks/shares, dividends, Korean Pfizer |
| 5 | Issues related to Janssen | 13.9% | Rounds, Janssen, domestic, additional vaccination, standard, youth group |
| 4 | Vaccine side effects | 13.3% | Severe, objects of prohibition, allergic reactions, composition, worried, death |
| Phase 2 | |||
| Topic Number | Topic | Percentage | Major Keywords |
| 5 | Vaccine side effects | 27.5% (1844/6706) |
Side effects, safety, symptoms, effect, clinical |
| 4 | Implementation of novel vaccines | 25.8% | Novavax, Covax, coming in, launch, supply, authorized |
| 1 | Issues related to vaccine procurement | 23.2% | Government, procurement, pharmaceutical company, contract, purchase, development |
| 3 | Vaccination | 12.3% | Vaccination, variety, quarterly, status, hospital, people |
| 2 | Current status of and information on COVID-19 | 11.2% | Virus, paramedic, high-risk medical institution, today |
| Phase 3 | |||
| Topic number | Topic | Percentage | Major keywords |
| 1 | Vaccination completion and booster shot | 46.2% (3286/7113) |
Vaccination, completion, booster shot, additional vaccination, cross-vaccination |
| 5 | Variant virus issues | 20.8% | Omicron, variant, COVID-19, infection, world |
| 3 | Vaccine side effects | 14.4% | Worried, sick, problems, vaccination |
| 4 | Implementation of novel vaccines | 10.1% | Sinopharm, Sinovac, KCDC, authorized, vaccines |
| 2 | Current status of and information on COVID-19 | 8.5% | Current, today, changes, fatality rate |