Assessment of the impact of the Vaccine Pass Policy on COVID-19 vaccine hesitancy and uptake among Chinese adults in Hong Kong

Summary Background Recognising the importance of attaining high vaccine coverage to mitigate the COVID-19 impact, a Vaccine Pass scheme was implemented during and after the first large Omicron wave in Hong Kong in early 2022 requiring three doses by June 2022. We evaluated the impact of the Vaccine Pass policy on vaccine uptake in adults. Methods We analyzed patterns in vaccine uptake and hesitancy using local data from the population vaccine registry and 32 cross-sectional surveys conducted from October 2021 to December 2022. We examined the association of Vaccine Pass phases with vaccine uptake, taking into account covariables including self-risk perception, perceived self-efficacy in preventing COVID-19 and trust in government in pandemic control as well as physical distancing measures and demographics. Findings The uptake of primary series and third doses was significantly associated with stages of Vaccine Pass implementation, and other statistically significant drivers included age group, chronic condition, higher perceived personal susceptibility to COVID-19, higher trust in government, and higher educational attainment. Older adults (≥65y) were less likely to be vaccinated against COVID-19, compared to adults aged 18-44 years. Interpretation Vaccine uptake in older adults was observed to have increased by a greater extent after the policy announcement and implementation, which occurred during and after a large Omicron wave with high mortality in older ages in early 2022. Since the policy withdrawal the uptake of further booster doses has been very low in all ages. Improving voluntary booster uptake in older adults should be prioritized. Funding Health and Medical Research Fund, Hong Kong.