Trends in Research about COVID-19 Vaccine Documented through Bibliometric and Visualization Analysis.

Due to COVID-19, people's lives have changed greatly. In accordance with former experience, an efficacious vaccine is the most effective way to curb the pandemic; thus, many researchers have published related publications in the short term. Hence, this study aims at using bibliometric analysis and visualization to document research trends regarding COVID-19 vaccines, and offer some directions and suggestions for future research. Initially, all eligible publications were downloaded from Web of Science on 1 January 2022. Subsequently, some publications published before December 2019 were removed since COVID-19 did not occur before that date. Finally, Microsoft Excel is used for bibliometric analysis to analyze publication date, author, affiliation, country, publication title, publisher, research area, document type, and language, and visualized software (VOSviewer) is used to visualize author, affiliation, country, and keywords. After analyzing a total of 17,392 publications, the results show that the overall research trend was upward. Moreover, the prominent authors, institutions, and countries inclined towards regional cooperation instead of international cooperation. Furthermore, the most popular research areas were immunology and medicine (general and internal). Ultimately, COVID-19, vaccine, and SARS-CoV-2 were the top 3 keywords. In conclusion, this study shows the approximate research trend for COVID-19 vaccine during the completely first two years of the pandemic. The research focuses moved from safety, effectiveness, and immunology at the early stage to the optimal allocation strategies for COVID-19 vaccine, and eventually to public attitudes and acceptance towards COVID-19 vaccination.