JMIR Publications

ABSTRACT

Background:

As COVID-19 transitions to an endemic phase, waning immunity and recurring waves point to the importance of sustained booster vaccination strategies. With repeated boosters needed to sustain population-level immunity, evaluating public preferences during the post-pandemic phase is critical, as changing perceptions of urgency, threat, and motivation may alter willingness to receive vaccine boosters compared with initial uptake.

Objective:

This study aimed to explore the Singapore public’s acceptance and willingness-to-pay for COVID-19 vaccine boosters and to identify the sociodemographic factors and health risk acceptance profiles associated with these outcomes.

Methods:

A discrete choice experiment (DCE) survey was conducted among the general population in Singapore recruited from an online panel in June 2022. DCE scenarios presented hypothetical scenarios varying by booster characteristics, including effectiveness, protection duration, and cost, and risks of COVID-19 infection, hospitalisation, and death. A two-stage discrete choice design was employed: participants first selected between two hypothetical scenarios, then reported real-life booster acceptance of their chosen option. A mixed logit model was used for analyses. We also estimated willingness-to-pay for vaccine booster, as well as assessed the associations of sociodemographic factors and health risk profiles with booster acceptance or hesitancy.

Results:

A total of 1567 participants were included in the analysis. Overall, the respondents preferred booster that offers longer duration of protection, particularly under higher risks of COVID-19 infection and death. Respondents were willing to pay S$1.43 for every percentage point increase in the booster effectiveness and S$4.95 per additional month of protection. Younger adults; women; individuals of non-Chinese ethnicity; those without children; people with higher socioeconomic status; individuals who had received two or fewer COVID-19 vaccine doses; and those with chronic conditions or on chronic disease medication were more likely to receive a booster. On the other hand, older adults, individuals with lower education or socioeconomic status, and those with prior COVID-19 infection, and those exhibiting higher health-risk-taking attitude were more likely to be hesitant towards booster vaccination.

Conclusions:

Our findings demonstrate how vaccine attributes, sociodemographic factors, and health-risk attitude influence booster acceptance. These insights can guide policymakers in tailoring strategies and communication efforts that address population needs and behavioural drivers to improve booster uptake, address hesitancy, and support sustainable long-term immunisation coverage, contributing to adaptive vaccination planning in the ongoing management of COVID-19.