Uma ameaça (In)visível: o paradoxo da baixa cobertura vacinal frente ao aumento da cobertura da Atenção Básica em Belo Horizonte, Minas Gerais

Abstract

Brazil has been considered one of the most successful countries in vaccination campaigns through the National Immunization Program (PNI), created in 1973 by the Ministry of Health. This occurred through the development of planned and systematized actions. With diverse strategies, it eradicated several diseases while controlling countless others. However, a global phenomenon has shown drops in vaccination coverage, including in Brazil, despite the existence of consolidated Primary Care in this country. In this study, the hypothesis was raised that there is a direct relationship between vaccination rates and Primary Care coverage. Therefore, the main objective of the research was to evaluate the influence of Primary Care coverage on vaccination coverage in children under one year of age for PNI immunobiologicals in Belo Horizonte, MG, from 2007 to 2020. A descriptive study of vaccination coverage was carried out of immunobiologicals offered in the BH vaccination network as well as the evolution of Primary Care in Belo Horizonte; the relationship between Primary Care coverage and vaccination coverage in Belo Horizonte was investigated and, finally, the existence of factors associated with changes in the vaccination coverage rate over time at a global level was verified. To this end, an ecological study was carried out in the capital of MG, from 2007 to 2020. Information made available in a public database was used, which was extracted in August 2023. A descriptive analysis of central tendency measures was carried out. and the D´Agostino Pearson Test was applied to verify the normality of the data. Between 2007 and 2020, Belo Horizonte showed significant variations in vaccination and Primary Care coverage rates. During this period, there was an increase in the number of ACS and ESF coverage, although with fluctuations. Vaccination coverage rates also fluctuated, with the lowest coverage occurring in 2014, and the highest values, in 2020, for most vaccines. Despite this, the immunization targets recommended by the PNI were not achieved for most vaccines, except for BCG. The inferential method was based on the application of structural equation modeling (SEM), which occurred through confirmatory factor analysis in order to define the constructs Basic Care (AT_BAS) and Vaccination Coverage (COB) based on the observed variables. Afterwards, Spearman's coefficient was applied to verify the relationship between them. The SEM showed a path coefficient of -0.0271 (very low) and p-value = 0.7854 (not significant) with R²: 0.9657 (good model performance). With this, it was evident that there was no correspondence between the variables AT_BAS and COB, in the period considered in the research, accepting the null hypothesis. A limitation of the study is that the data reflects the municipality of Belo Horizonte as a whole, without taking into account the socioeconomic disparities between its regions. Furthermore, data from information systems were used, which may be underestimated due to underreporting and delays in updating.