ABSTRACT
Objectives: Brazil's annual vaccination coverage rate (AVCR) for Polio has risen to alarming levels in recent years. Given the imminent possibility of the return of the disease eradicated 32 years ago in Brazil, the objective was to assess the historical data of AVCR and foresee the Brazilian performance in the next five years. Method(s): We apply a classic linear forecasting model Holt Winter (HW), composed of a forecasting equation and three corresponding smoothing equations alpha, beta, and gamma. The Polio AVCR between 1994 and 2022 was collected from the National Immunization Program and was evaluated in two stages using the R software involving (i) analysis of data, (ii) application of the HW using least squares adjustment. Result(s): The AVCR showed a growing trend between 1994 (38%) and 1999 (86%). From 2000 to 2015, the average AVCR was 78.72%, with the best coverage in 2015 (95.07%). Between 2016 and 2022, the AVCR was 66.75%, with a tendency to reduce over time. Between 2020 and 2022, AVCR had its lower result (64.44%), which can be explained by the postponement of Polio vaccination due to the COVID-19 pandemic. The best adjustment of smoothing alpha, beta and gamma was achieved (0.67, 0, 0) by HW. The forecast showed positive results in the average AVCR, with a growth of 16.71% in the next five years and with an AVCR projection of just 75.89%, in the case of no public health action is endowed by the country. To reach the best AVCR achieved in 2015, it is necessary to expand it by 48.5%. Conclusion(s): Forecasts using HW are recommended for public health monitoring, helping managers make decisions with limited resources. The results indicate that it is necessary to develop a strategic plan to expand AVCR to keep Polio eradicated from Brazil, mainly due to both disease gravity and treatment unavailability.Copyright © 2023