Abstract
BACKGROUND: People experiencing homelessness (PEH) have an increased risk of all-cause mortality, higher rates of vaccine-preventable diseases (VPDs), and poorer related health outcomes compared to the general population. At the same time, delivering vaccinations within this vulnerable group is complex, and there is limited evidence to inform practice in this field. This study aims to explore the key determinants influencing vaccination willingness among PEH. METHODS: Cross-sectional survey of PEH at shelters, night shelters, and free-meal sites in Warsaw (Sep 2024-Aug 2025; convenience sampling). Analyses used ETHOS-weighted descriptives (95%CIs) and logistic regression comparing reluctant (unsure or unwilling) vs. willing (secondary: unwilling vs. willing), adjusted for prespecified sociodemographic and homelessness characteristics. RESULTS: Of 275 PEH surveyed, 215 (78.2%) were male, and 60 (21.8%) were female. Based on FEANTSA (European Federation of National Organisations Working with the Homeless) categories, 162 (58.9%) were classified as Roofless, 85 (30.9%) as Houseless, and 11 (4.0%) as Insecure. Weighted mean age was 52.6 years (95% CI: 50.9-54.2). The majority of the surveyed individuals have completed secondary education (37.1%), followed by vocational (31.6%), primary (20.7%), and higher (9.8%); two participants (0.7%) had not completed primary school. Overall vaccination willingness was 69.9% (95%CI 63.1-76.0). Unwillingness and uncertainty were 24.0% (95%CI 18.5-30.5) and 6.1% (95%CI 3.4-10.6), respectively. Lower odds of reluctance were observed for secondary/higher education (vs. primary; OR 0.40, 95%CI 0.22-0.76), Roofless individuals (OR 0.46, 95% CI 0.24-0.89), and those experiencing homelessness for a prolonged period of time (per 1-SD, OR 0.59, 95%CI 0.40-0.86). Sex, age, and chronic illness were not significant. Across attitude items, lower perceived effectiveness and lower personal benefit showed the strongest associations with reluctance; safety concerns were modest. As compared to the full sample, reluctant respondents were about two times more likely to endorse low-benefit/low-effectiveness statements, while safety concerns were common in both groups. CONCLUSIONS: About two-thirds of respondents were willing to vaccinate. Reluctance was most strongly associated with lower perceived vaccine effectiveness and personal benefit. Interventions should address these beliefs and prospectively evaluate whether changes to them translate into greater willingness and, ultimately, higher uptake.