The purpose of this study is to review the discourse on vaccination from a critical perspective by considering coronavirus disease 2019 (COVID-19) news on web portals to be practical arguments advocating for certain actions. For this purpose, this study analyzed the argument patterns of the discourse on vaccination with the keyword COVID-19 vaccine side effects and examined discourse characteristics highlighted by media reports to evaluate their meaning. Contrasting patterns were observed between pro- and anti-vaccine arguments, which consisted of the necessity of vaccination and medical evidence and which focused on personal choice and vaccine side effects, respectively. The characteristics of the political discourse were observed in the contest between these arguments. Rhetorical phrases, which are often used in the political discourse, represented the misleading arguments that lacked evidential accuracy and argumentative validity by maximizing fear, instead of alleviating fear about a health crisis with scientific information and discussion. As fake news trending on social media was introduced to online news portals, which are regarded as public discourse platforms, and undermined trust in the public discourse, it served as an opportunity to politicize the discourse on vaccination.

To clarify the concepts of dialects, vernacular and regional languages used with similar meanings, this study attempted to reveal the usage patterns and concepts of these expressions based on written corpus. The written corpus of printed newspaper articles from the online Naver News Library that archived newspaper articles from 1920 to 1999 and the news article corpus crawled by the online Naver News portal from January 1, 2004 to December 31, 2021 were extracted and analyzed. In particular, this paper analyzed the relationship between collates and keywords based on the corpus linguistic research methodology of the news article corpus for the past eighteen years and how they were being used in official records and press documents by corresponding with the 'dialects, vernacular, and regional languages' in socio-linguistic terms of modern Korean. The results are summarized as follows. First, the concept of linguistic norms that a dialects have terms corresponding to the words or standard languages was established after the 1930s. Second, in the library of newspaper articles published in the 20th century, dialects or vernaculars were perceived as negative objects to be removed in preparation for standard language. Third, it can be seen that the positive value judgment on 'vernacular' has increased in the corpus of news articles over the past decade. Fourth, dialects and vernacular, regional language, and standard language were used to be compatible with each other, and it can been seen that dialects were mainly used in academic contexts and vernacular were mainly used in everyday contexts. Fifth, it can be confirmed that the positive perception of standard language has been maintained in the 20th-century newspaper article corpus and the 21st-century news article corpus for the last eighteen years after the recognition of standard language.