Determinants for COVID-19 vaccine hesitancy in the general population: a systematic review of reviews

Aim: Although multiple COVID-19 vaccines are approved for global use, vaccine hesitancy poses a substantial risk for global health. Therefore, the aim of this umbrella review is to identify those factors that influence COVID-19 vaccination hesitancy in the general population. This is necessary to improve the effectiveness of future vaccination programmes. Methods: PubMed, Embase, Scopus, PsycInfo, the Cochrane Database of Systematic Reviews, Epistemonikos, and PROSPERO (International Prospective Register of Systematic Reviews) were searched on December 21, 2021. This review included reviews which investigated factors of intention, willingness, or hesitancy with regard to the COVID-19 vaccination in adult populations, with no restrictions on setting. Content-based structure was used to synthesise the extracted data. The findings were presented based on the Strategic Advisory Group of Experts (SAGE) Working Group Model for vaccine hesitancy. Results: A total of 3,392 studies were identified, of which 31 met the inclusion criteria. The most frequently documented factors associated with COVID-19 vaccine hesitancy included contextual factors, such as sex, age, and social inequalities; individual and group factors, such as trust in the healthcare system, public health authorities, and governments, and history of vaccination; vaccine-specific factors, such as concern for vaccine safety, perceived vaccine barriers, perceived effectiveness of vaccines, and concern about the rapid development of the vaccine; and disease-specific factors, such as fear of being infected with COVID-19, perceived severity of COVID-19, and knowledge of COVID-19. Conclusion: There are multiple factors associated with COVID-19 vaccine hesitancy. Our findings lay the foundation to further understand COVID-19 vaccination uptake and provide possible targets for intervention programmes. However, there are gaps in research concerning certain populations, including vaccination in people with mental disorders