Risk classification for the transmission of vaccine-preventable diseases in the state of Minas Gerais, Brazil: 2018 to 2022.

The National Immunization Program (PNI) is one of Brazil's most significant public health interventions. However, recent years have witnessed a progressive decline in vaccination coverage despite the success of the PNI and the expansion of Primary Health Care (PHC), the main point of entry for the population into health services. To address this challenge, broader strategies are needed, such as identifying areas at high risk for the transmission of vaccine-preventable diseases. This study aimed to analyze the risk classification for the transmission of vaccine-preventable diseases in the 853 municipalities of Minas Gerais, Brazil, from 2018 to 2022. This epidemiological time-series study uses secondary data on vaccination coverage, dropout rates, and homogeneity of the recommended immunobiologicals for children under 2 years of age from 2018 to 2022 in Minas Gerais. We obtained the data from the National Immunization Program Information System (SIPNI). The study highlighted a decline in vaccination coverage from 2018 to 2021, with a significant drop following the COVID-19 pandemic in 2020. According to the risk classification for the transmission of vaccine-preventable diseases, the proportion of municipalities classified as high and very high risk remained stable from 2018 to 2019, increased from 2019 to 2020 and from 2020 to 2021, and decreased from 2021 to 2022. We observed the public health impact not only regarding COVID-19 but also on most vaccine-preventable diseases. Given the scenario of declining vaccination coverage and the risk of a resurgence of vaccine-preventable diseases exacerbated by the COVID-19 pandemic, health services must implement public health strategies to mitigate this situation. Risk classification proved to be an effective methodology for prioritizing locations for health interventions. It enabled the analysis of the vaccination scenario in the state following the implementation of a participatory action research project conducted jointly by academia and health services.