Determinants of vaccine uptake in the elderly. Results from a mobile health clinic survey in Italy

Abstract Background Vaccination is one of the most effective public health tools for improving the quality of life of adults and reducing healthcare utilisation. Despite numerous vaccination campaigns targeting this population, vaccine uptake is generally low. The aim of this study was to investigate the main determinants of vaccine uptake in people aged 65 years and over. Methods A mobile health clinic initiative for health promotion has been set up in a railway wagon in the Veneto Region, Italy, in October 2022. Access was free and voluntary. Information was collected on age, gender, nationality, education level, BMI, as well as on smoking, physical activity, vegetable consumption and presence of hypertension, hypercholesterolemia and diabetes. Uptake of flu, zoster, pneumococcal and tetanus vaccines was reported by participants, as was any recommendation by healthcare professional. The effect of the variables on uptake was assessed using a multivariable logistic regression. Results A total of 638 participants were included, of whom 50.9% female. Mean age 72.6±6.1. Uptake of flu vaccine was 61.8%, while zoster 17.1%, pneumococcal 21.6% and tetanus 10.0%. The main factor for uptake was having received a recommendation from a healthcare professional (flu: AOR=4.29 95%CI 2.77-6.63; zoster: AOR=3.12, 95%CI 1.52-6.40; pneumococcal: AOR=5.11, 95%CI 2.50-10.44; tetanus: AOR=14.23, 95%CI 4.20-48,35). Flu vaccine uptake was associated with hypertension (AOR=1.77, 95%CI 1.03-3.06) and smoking (AOR=1.84, 95%CI 1.04-3.25). No association was found with other comorbidities, lifestyle or SES. Conclusions Population growth and increasing average life expectancy in Europe make vaccine uptake by older adults an integral part of a healthy lifestyle. Among factors involved in the decision whether or not to vaccinate, the recommendation from a healthcare provider remains the most important determinant, and this is more evident in the absence of specific campaigns, as in the case of tetanus. Key messages • Among possible determinants, recommendation from a healthcare provider is associated with a significantly higher uptake for flu, zoster, pneumococcal and tetanus vaccine in the 65+ population. • The magnitude of this effect is even greater in the absence of specific campaigns, as in the case of tetanus, when it increases uptake 14-fold.