# Beyond the Virological Benefits of the Herpes Zoster Vaccine in the Context of Primary Care

## TL;DR

This study finds that the herpes zoster vaccine is linked to reduced risk of vascular events and that social factors strongly influence vaccination rates.

## Contribution

The study identifies socio-environmental factors as key predictors of HZ vaccine adherence and demonstrates its protective effect against vascular events.

## Key findings

- HZ vaccination is independently associated with reduced risk of acute vascular events.
- Socioeconomic status and education level strongly influence HZ vaccine adherence.
- Chronic diseases correlate with higher adherence to pneumococcal and influenza vaccines but not HZ vaccine.

## Abstract

Background/Objectives: Recently, the Herpes Zoster (HZ) vaccination has been introduced, alongside influenza and pneumococcal vaccination, at age 65. Factors influencing adherence to this vaccination and its clinical benefits are not completely understood. The aim of this study was to evaluate factors influencing adherence to HZ vaccination compared to pneumococcal and influenza and to assess its clinical effect in preventing acute vascular events. Methods: A total of 1152 patients (520 males), having a birth cohort from 1952 to 1959 inclusive, was recruited, belonging to the District of Udine (N = 839) and to the ASAPs 2 and 3 of Pordenone (N = 313). For each patient, a form was compiled. Results: HZ vaccination was administered to 498 patients, influenza to 665, and pneumococcal to 742 (p < 0.0001). Among the vaccinated, 266 received the live-attenuated version, and 232 the recombinant HZ vaccine. In logistic regression, the presence of addictions, low educational level, and poor socioeconomic status were strongly associated with lower vaccine adherence. The presence of chronic diseases enhanced only pneumococcal (p < 0.001) and influenza (p < 0.001) vaccine adherence. Forty-two non-fatal acute vascular events were recorded from age 65 onwards: 14 cardiac, 20 cerebrovascular, and 8 peripheric. Only 6/493 patients experienced an event following HZ vaccination compared to 36/659 unvaccinated subjects (p = 0.0003). In Cox modeling, HZ vaccination proved to be an independent predictor in preventing subsequent acute vascular events (p < 0.001). Conclusions: The presence of pathologies does not enhance adherence to HZ vaccination while an unfavorable socio-environmental context greatly hinders it. HZ vaccination, but not influenza and pneumococcal vaccination, appears to protect against the occurrence of acute vascular events.