Abstract
BACKGROUND: The emergence of new COVID-19 variants continues to affect healthcare workers (HCWs) and vulnerable populations in the post-pandemic era. This study aims to assess the willingness, perceptions, and factors associated with booster COVID-19 vaccine uptake in this context. METHODS: A cross-sectional study was conducted between October 2023 and May 2024 among Thai adults (>20 years old) in Chiang Mai, Northern Thailand. Participants included HCWs and patients with chronic medical conditions. People who had received a monovalent XBB-derived booster vaccine were excluded. RESULTS: Data related to a total of 811 participants were analyzed, with 328 from the vulnerable group and 483 HCWs. Willingness to receive the booster was similar in both groups (43.3% in HCWs, 45.0% in the vulnerable group). Low-risk perception (59.6%-83.5%), minimal impact on daily life (60.4%-62.9%), and doubts about booster efficacy (75.9%-81.4%) were prevalent negative thoughts toward the booster. Having received a flu vaccine (aOR 2.1), concerns about the impact on life of COVID-19 (aOR 1.8), and beliefs in booster safety (aOR 1.8) and vaccine effectiveness against severe disease (aOR 2.7) were associated with increased willingness. CONCLUSIONS: Only 44% of participants were willing to receive a COVID-19 booster. Policymakers can use these insights to develop strategies to increase vaccine uptake in the post-pandemic era.