Ecological Study on the Administration of Oral Polio Vaccine (OPV) in Children in Araguari-MG fom 2018 to 2022

Abstract

Introduction: Poliomyelitis is a highly contagious disease that can cause irreversible paralysis and death, especially in children. In Brazil, the introduction of the oral polio vaccine (OPV) in the 1960s was crucial for eradicating the poliovirus, with the last case reported in 1989. However, the COVID-19 pandemic negatively affected childhood vaccination coverage, increasing the risk of reintroducing the disease. This study aims to analyze OPV administration in children in Araguari, Minas Gerais, between 2018 and 2022, identifying adherence levels and potential coverage gaps.

Methods: This is an exploratory ecological study with a quantitative approach, using secondary data from the National Immunization Program Information System (SI-PNI) – DATASUS. The study focused on children aged 1 to 4 years, using population estimates from the Brazilian Institute of Geography and Statistics (IBGE) to calculate coverage rates based on the number of doses administered.

Results: OPV coverage rates fluctuated during the study period. Rates were relatively high in 2018 and 2019 but dropped sharply in 2020 and 2021, falling below 60% in some age groups, especially among 1- and 4-year-olds. In 2022, a partial recovery was observed, though coverage remained below the 95% target set by the National Immunization Program (PNI).

Discussion and Conclusion: The decline in coverage is associated with health service disruptions, vaccine hesitancy, and misinformation. The findings underscore the need for strengthened immunization strategies and public awareness to prevent the reemergence of poliomyelitis in Brazil.