Bibliometric and Visual Analysis of Vaccination Hesitancy Research from 2013 to 2022

"...wish to give a boost to address vaccine hesitancy, especially in regions where populations have a low acceptance of vaccines and are at risk of low immunization rates and encourage policymakers to take measures to tackle this challenge."

Vaccine hesitancy refers to delay in acceptance or refusal of vaccination despite availability of vaccination services. Since the outbreak of coronavirus disease 2019 (COVID-19), more and more attention has been paid to this issue. Bibliometrics is an emerging field of information science that can help clarify the structural features and evolution process of one research area through an analysis of a field's scholarly output as captured in the published literature. This study used a bibliometric analysis to provide an overview of vaccination hesitancy research from 2013 to 2022. The goal is to demonstrate the current research status, provide insight into the growth of vaccination hesitancy research publications, identify potential influencing factors of vaccination hesitancy, and possibly inspire research ideas for future direction in the field.

Data collection was conducted on December 15 2022. All related publications were retrieved from the Web of Science Core Collection Database. Information on annual publications, countries, organisations, journals, authors, keywords, and documents was analysed adopting the bibliometix R-package, VOSviewer, and CiteSpace software. A total of 4,042 peer-reviewed publications, including 3656 articles and 386 reviews, were enrolled. Selected findings:

• The most frequent keywords were "vaccine hesitancy", "COVID-19", "SARS-CoV2", "immunization", "attitudes", and "willingness".
• Psychological factors such as misinformation, risk perception, and cognitive biases attracted increasing attention. The importance of social and cultural influences on vaccine acceptance comprising community norms, religious beliefs, and trust in healthcare systems was also recognised.
• The impact of digital media and social network platforms in delivering vaccine-related information, as well as shaping public attitudes, was also acknowledged. Digital technologies and social media platforms were also utilised to deliver accurate information and counter misinformation.
• Some new barriers came into focus. Specific concerns and hesitancy patterns related to COVID-19, human papillomavirus (HPV), and influenza vaccines were emerging. Socio-economic factors such as income disparities and access to healthcare were recognised as significant barriers to vaccine acceptance.
• During the study period, the development of targeted communication campaigns tailored to specific populations to some extent addressed their concerns and misinformation. In addition, collaboration between healthcare providers, public health agencies, and community organisations was a key strategy for improving vaccine acceptance and uptake.
• The annual publications increased slightly before 2020 but had an extremely dramatic increase from 2020 to 2022 - namely, there was a more than 40-fold increase in annual publications in 2021 and 2022. Compared with previous pandemics before COVID-19, this spike in the field was noteworthy. Factors causing the difference might include the urgency and global reach of COVID-19 pandemic and the increased public attention and media coverage.
• Among the 987 journals represented, Vaccine was the most cited journal, while Vaccines was the most productive journal.
• 154 countries and regions participated in the vaccination hesitancy research included in this review. The United States contributed the most articles and had the most collaboration with other countries and organisations.
• 5,468 organisations were involved in the research included in this review. The London School of Hygiene & Tropical Medicine was the most active institution.
• Of the 19,165 researchers whose work was included in the review, Dube E, Verger P, Omer SB, Larson HJ, and Leask J were the top five most productive authors in the field.

In conclusion: "A large amount of literature in the research area has focused on the causes and impacts of vaccination hesitancy. The influencing factors vary across time, space, and vaccines....The complexity and specific contexts of influencing factors of vaccination hesitancy require further study. Future research may further explore the role of social media and misinformation, identify, and address cultural and linguistic barriers, investigate the impact of vaccine-related adverse events, and recognize the role of the health-care providers."