Análise espacial e temporal da cobertura vacinal contra a poliomielite nas cidades brasileiras de fronteira entre 2016-2024

Abstract

Introduction: Vaccination is one of the most effective strategies for controlling vaccine-preventable diseases, reducing the transmission of infectious agents, preventing severe disease forms, and eradicating pathologies. Its importance for Public Health lies in contributing to disease control and elimination. However, the decline in polio vaccination coverage in Brazil poses a significant risk of virus reintroduction, given that rates remain below the target (95%) recommended by the Ministry of Health and the World Health Organization. Objective: To analyze the spatiotemporal dynamics of polio vaccination coverage in Brazilian border cities between 2016 and 2024. Methods: A mixed ecological study was conducted using publicly available secondary data. Data on administered doses were extracted from the National Immunization Program Information System, while live birth records were obtained from the Live Birth Information System of the Unified Health System’s Department of Informatics. Vaccination coverage (VC) was calculated by dividing the number of administered doses by the number of live births, multiplied by 100. Descriptive analyses, Kruskal-Wallis tests, Dunn’s multiple comparisons, and Mann-Whitney U tests were performed. Spatial analyses were conducted using Global and Local Moran’s indices. Statistical analyses were performed using SPSS 24.0 and QGIS 3.10, with a significance level of 5%. Results: Significant differences in VC were observed across study years (Kruskal-Wallis test,*p*< 0.001). Dunn’s post-hoc test indicated that 2016 had the highest VC compared to other years (*p* < 0.05). Although VC increased in 2022 and 2023 relative to 2021, it remained below the 95% target (*p*< 0.001). By 2024, VC recovered, surpassing 95% and differing significantly from 2021, 2022, and 2023 (*p*< 0.001). In most study years, VC in twin cities was lower than in non-twin cities (*p*< 0.05). Positive global spatial autocorrelation was detected throughout the study period. Spatial analysis of polio VC across 590 Brazilian border municipalities revealed significant variations in coverage distribution from 2016 to 2024. Conclusion: This study situates itself at the forefront of research by proposing a novel binational intervention model for border regions, gap identified by PAHO (2023). The findings not only replicate but expand the existing literature, providing an analytical framework for future health research in Brazilian border areas.