Spatial patterns of vaccination coverage against covid-19 in elderly people and their relationship with the social vulnerability index in piauí: an ecological study

Abstract

Objective: To analyze the spatial distribution of COVID-19 vaccination coverage among elderly individuals in the state of Piauí and its relationship with the Social Vulnerability Index, identifying spatial patterns and clusters that may reflect inequalities in access to vaccination. Method: This is an ecological study with a quantitative approach. The population consisted of all vaccination records of individuals residing in the state of Piauí aged ≥60 years, covering the period from January 2021 to December 2024. Data on COVID-19 vaccination were obtained from OpenDataSUS. The Social Vulnerability Index was obtained from the Institute of Applied Economic Research. Statistical analysis was performed using RStudio 2024.12.0+467 software, while spatial analysis was performed using GeoDa 1.22.0.4. Results: The results showed significant spatial patterns, with clusters that highlighted inequalities in the distribution of health services in the state of Piauí. In certain regions, an association between high vaccination coverage and low social vulnerability was observed. However, the global Moran's I of -0.02 indicated low spatial autocorrelation in the state as a whole, reflecting the local variability of these relationships. Thus, the low global spatial autocorrelation suggests that these associations vary according to the regional context. Conclusion: The study revealed the existence of spatial patterns in the distribution of vaccination coverage against COVID-19 among the elderly in the state of Piauí, highlighting inequalities in access to health services. These findings reinforce the need to improve registration systems and formulate public policies that ensure a more equitable distribution of vaccination.