Prevalence and determinants of COVID-19 vaccine acceptance among vulnerable populations in Thailand: An application of the health belief model

Background: Assessing the acceptance of vaccinations among vulnerable populations is essential to ensure proper coronavirus disease 2019 (COVID-19) control. This study used the Health Belief Model to examine the intention to vaccinate against COVID-19 among vulnerable populations in Thailand. Methods: This analytical cross-sectional study was conducted in Thailand between October and November 2021. Using multistage random sampling, 945 individuals from vulnerable populations (i.e., older adults, pregnant women, market or street vendors, and individuals with chronic diseases) were selected and invited to complete a self-reported questionnaire. The questionnaire assessed participants' socioeconomic characteristics, COVID-19 preventive measures, knowledge, preventative health beliefs, and vaccine intention. A generalized linear mixed model was used to identify factors associated with the intention to receive the vaccine. Results: The prevalence of intent to accept the COVID-19 vaccine was 75.03% (95% confidence interval [CI]: 72.16-77.68). The Health Belief Model factors associated with vaccine acceptance were cue to action (adjusted odds ratio [AOR] = 3.13; 95% CI: 2.07-4.71), perceived benefits (AOR = 2.04; 95% CI: 1.38-3.01), and perceived severity (AOR = 1.77; 95% CI: 1.18-2.65). Significant other covariates were wearing a face mask in the previous month (AOR = 2.62; 95% CI: 1.59-4.31), being 1-2 m away from other people (AOR = 1.58; 95% CI: 1.11-2.24), trust in government (AOR = 1.44; 95% CI: 1.03-2.02). Additionally, women were more likely to accept the COVID-19 vaccine compared to men (AOR = 1.43; 95% CI: 1.02-2.01). Conclusions: Approximately one quarter of vulnerable individuals do not intend to be vaccinated. Health Belief Models can explain vaccine acceptance, and aid the Ministry of Public Health in planning future efforts to increase vaccine uptake. Healthcare professionals' advice, village health volunteers' information, and partnership collaborations are critical. Facilitating mobile community units, launching educational campaigns, maintaining a distance of 1-2 m from others, and wearing masks may increase COVID-19 vaccine acceptability. This research can help prepare for future pandemics.