High-Cited Papers in Global COVID-19 Vaccine Research

Background and Aim: The coronavirus disease 2019 (COVID-19) virus pandemic is still ravaging the world with its ongoing resurgence and continuous mutation, suggesting the need for continuous research on safe and effective novel vaccines. Presently several types of vaccines have been developed and emerged in the global market to control COVID-19 virus. Consequently, the knowledge and information on COVID-19 have been expanding at a high level. Researchers need to gain relevant knowledge regarding the different vaccines; however scattered information makes this process time-consuming and laborious. The present study aimed to evaluate the characteristics and trends in global COVID-19 vaccine high-cited literature using bibliometric and visualizations methods and offer some directions and suggestions for future research. Methodology: Studies published between December 2019 and 22 Nov 2022 on COVID-19 vaccines were retrieved from the Scopus database. From the 16026 studies retrieved, 406 were identified as high-cited papers (HCPs) having received 100 or more citations. From the 406 HCPs, information about publications outputs, countries, institutions, journals, keywords, and citation counts was identified. Data analysis and visualization were conducted using Microsoft Excel, VOSViewer and Bibliometrix R software. Results: The 406 global HCPs on COVID-19 vaccines research were identified in Scopus database since Dec 2019 till 30 Nov 2022 using a search strategy, which received 123614 citations, averaging 304.17 citations per publication (CPP). An external funding was received by 53.20% (216 publications), which were cited 76107 times (with an average of 352.35 CPP). The 7086 authors from 694 organizations affiliated to 76 countries and publishing in 121 journals were involved in global COVID-19 vaccine research. The most productive countries were USA (n=213), U.K (n=91), China (n=36) and Germany (n=35). The most impactful countries in terms of citations per paper (CPP) and relative citation index (RCI) were South Africa (794.68 and 2.61), Germany (507.11 and 1.67), U.K. (396.59 and 1.30) and Spain (367.5 and 1.121). The most productive organizations were University of Oxford, U.K., Imperial College London, U.K. (n=25 each), Center for Disease Control & Prevention (CDC), USA and Tel Aviv University (n=19 each) and the most impactful organizations were University of Cambridge, U.K (783.4 and 2.57), Emory University, USA (780.1 and 2.56), John Hopkins Bloomberg School of Public Health, USA (702.67 and 2.31) and National Institute of Allergy & Infectious Diseases. USA (676.41 and 2.22). The most productive authors were A.J. Pollard (n=16) and T. Lambe (n=14) (of University of Oxford), O. Tureci and P.R. Dormitzer (n=12 each) (of BioNTechSE, Germany) and the most impactful were D. Cooper (1239.22 and 4.07), K.J. Janseu (1228.11 and 4.03) (BioNTechSE, Germany, K.A. Swanson (987.0 and 3.24) (University of Oxford, U.K.) and P.R. Dormitzer (983 and 3.23) (BioNTechSE, Germany). The most productive journals were New England Journal of Medicine (n=53), The Lancet (n=28), Nature (n=22) and JAMA (N=17). The most impactful journals (as per citations per paper) were New England Journal of Medicine (613.15), Lancet (496.39), Human Vaccines and Immunotherapeutics (369.67) and Nature (360.64). Among population age groups, the major focus was on adults (51.48%) and Middle Aged (39.16%). Among publication types, the major focus was Clinical Studies (26.85%), Epidemiology (22.66%) and Genetics (21.92%). The most significant keywords by frequency of appearances were “COVID-19” (n=388), “COVID-19 Vaccines” (n=357), “Vaccination” (n=221), “Prevention & Control” (n=181) and “Vaccine Immunogenicity” (n=133). Conclusion: The HCPs in COVID-19 vaccine research was done mainly by the authors and institutions of high-income countries (HIC) and was published in high-impact medical journals. Our research has identified the leading countries, institutions, journals, hotspots and development trend in the field that could provide the foundation for further investigations. The bibliometric analysis will help the clinicians to rapidly identify the potential collaborative partners, identify significant studies, and research topics within their domains of COVID-19 vaccines.