RESUMEN
Objectives: Acceptance and high uptake of COVID-19 vaccines continues to be critical for controlling the COVID-19 pandemic. This narrative review aimed to summarise findings on factors influencing acceptance of COVID-19 vaccines in the period leading up to the approval and rollout. Methods: We conducted a narrative review of literature published in 2020 on factors influencing acceptance of hypothetical COVID-19 vaccines in adults in high income countries with well-established health systems. Results: Facilitators of acceptance included confidence in vaccine safety and effectiveness, high COVID-19 disease risk perception and trust in health authorities and other vaccine stakeholders, including government. Barriers included safety and effectiveness concerns, perceived scientific uncertainty, low disease risk perception, and low trust in authorities and other stakeholders. Conclusion: Evidence on facilitators and barriers to COVID-19 vaccine acceptance, at a time prior to vaccine rollout, can help health authorities address hesitancy and may inform approaches to support acceptance of novel pandemic vaccines in the future. Future research should include in-depth qualitative research to gather more nuanced evidence.