Longitudinal patterns and predictors of COVID-19 vaccine confidence from pre-vaccine rollout to mass vaccination: A population-based cohort study.

BACKGROUND

Vaccine confidence is crucial for achieving high vaccination rates against COVID-19, yet vaccine confidence varied significantly throughout the pandemic. This study assessed the trajectories and predictors of COVID-19 vaccine confidence from prior to the vaccine rollout to mass vaccination.

METHODS

It is a population-based cohort study with nine waves of longitudinal data from September 2020 to February 2023, spanning the pre-vaccine rollout to COVID-19 mass vaccination in Hong Kong. We derived a composite score of COVID-19 vaccine confidence from the Vaccine Confidence Index and used group-based trajectory modelling to identify trajectories of COVID-19 vaccine confidence. Multinomial logistic regression and generalized estimating equations were used to identify baseline and time-varying predictors of COVID-19 vaccine confidence.

RESULTS

Four distinct trajectories were identified: persistently confident (17.2 % of the sample), mildly ambivalent (58.3 %), moderately ambivalent (19.4 %), and persistently hesitant (5.0 %). Women, young and middle-aged adults, individuals with higher educational attainment, and those with non-establishment political views were less likely to be persistently confident about COVID-19 vaccines. Misconceptions regarding older adults and chronic diseases were associated with lower COVID-19 vaccine confidence in all groups. Mistrust in health authorities, doctors, and academics was associated with lower confidence in the ambivalent or hesitant groups.

CONCLUSIONS

Our findings suggest substantial heterogeneity in the trajectories of COVID-19 vaccine confidence, underscoring the need for early interventions to improve vaccine confidence and vaccine uptake. Engendering trust in health care professionals, academics, and public health agencies may be particularly useful among ambivalent or hesitant individuals.