The role of sociodemographic factors on herpes zoster vaccine uptake among hard-to-reach populations

Abstract Background The anti-Herpes Zoster (HZ) vaccination program was expanded with the adjuvated recombinant vaccine (HZR) in the Lazio Region, Italy, in 2022, restricting its use only to certain categories at risk due to pathological conditions, such as dialysis patients or immunocompromised individuals. This study focuses on the role of clinical and socio-demographic factors on HZR vaccine uptake within the fragile resident population of the Local Health Authority Rome 2 (ASL RM2). Methods This population-based, retrospective cohort study leveraged data from various registries and databases. The study population comprised 835,779 individuals aged ≥18 years who were both RM2 residents and registered with an RM2 general practitioner (GP). Among these, 143,242 individuals with at least one chronic condition were assessed for vaccination uptake using a multivariate logistic model, exploring associations with gender, age, nationality, marital status, household size, and level of deprivation. Results At the conclusion of the study period, a small fraction (1.5%) of the fragile subjects had received at least one dose of the HZR vaccine, and a majority (78%) completed the vaccination course of two doses. The analysis indicated that vaccine adherence was significantly higher in males (OR = 1.15) and individuals aged 65 + (OR = 1.13) while lower among residents in areas of medium (OR = 0.61) and high deprivation (OR = 0.44) and with specific living arrangements - widowed people living alone (OR = 0.66) and families ≥ 6 people (OR = 0.63). Conclusions The ASL RM2 vaccination strategy for hard-to-reach individuals includes an integrated approach, with the engagement of local healthcare facilities and hospitals. Despite these efforts, lower adherence in socioeconomically disadvantaged fragile patients suggests a pressing need for targeted communication strategies and interventions to ensure equitable access to the HZ vaccine, as these groups are more vulnerable to developing chronic diseases. Key messages • Socio-demographic factors significantly influence Herpes Zoster vaccine uptake in hard-to-reach populations, with lower adherence in socially deprived groups. • Tailored, equity-driven approaches are essential for enhancing vaccine coverage among hard-to-reach fragile individuals, mitigating the higher disease risks in these communities.