COVID-19 Vaccine Preferences in China: A Comparison of Discrete Choice Experiment and Profile Case Best-Worst Scaling

Little is known about the diversity of residents' preferences for COVID-19 vaccines during the time when COVID-19 management was downgraded in China. This study aims to investigate these preferences using discrete choice experiment (DCE) and profile case best-worst scaling (BWS-2), and to assess the concordance between these two methods.

Chinese residents recruited for the online survey were asked to evaluate COVID-19 vaccine profiles through both DCE and BWS-2 from April to July 2023. Attributes included effectiveness, duration of protection, risk of severe adverse events (degree), the total out-of-pocket (OOP) cost, brand, and the vaccination method. We utilized conditional regression and mixed logit regression models to estimate the preference levels for potential attributes. To assess preference concordance between the two methods, re-scaling and the Spearman correlation test were used. Additionally, subgroup analysis was conducted to determine the most suitable method for different population groups, categorized by vaccine hesitancy and risk level.

A total of 438 (71.22%) respondents were included. A similar pattern was found in the DCE and BWS-2 methods, with the respondents having a strong preference for 90% vaccine effectiveness. However, the methods diverged in other preferences; DCE favored domestic brands and low severe adverse event risk, while BWS-2 preferred moderate risk and three years of protection. Concordance assessment, including Spearman's correlation and linear regression, showed no significant correlation and poor concordance between the methods, underscoring these differences. Preference heterogeneity is revealed among different groups; however, effectiveness remained the most important attribute for all subgroups of the population. Oral vaccination was the preferred option for both the vaccine-hesitant and high-risk groups.

This study offers new insights into the varying preferences for COVID-19 vaccines among Chinese residents following the downgrading of pandemic management measures. The findings underscore the need for diverse strategies in vaccine policy design. Special emphasis should be placed on vaccine attributes that align with public priorities, such as high effectiveness and low risk levels, to enhance vaccine uptake.