RESUMEN
Introduction: the first COVID-19 case in Brazil was confirmed on February 26, 2020. As of March 17, 2023, the Ministry of Health reported 699,634 deaths from COVID-19, with a case fatality rate of 1.9%. The impact of the COVID-19 pandemic in Brazil extends to socioeconomic and healthcare systems, reflecting significant regional disparities. Objective: To analyze mortality, incidence, and case fatality rates for COVID-19 in the states of Paraná and Santa Catarina, in the southern region of Brazil. Methods: This is an ecological time-series study using official Brazilian secondary data for COVID-19 cases and deaths. Data were extracted from the dashboard of the State Health Department of Santa Catarina and Paraná. Temporal series were developed for trend analysis using the Prais-Winsten regression model. Statistical analyses were performed using STATA 14.0 software (College Station, TX, USA, 2013). Results: In the analysis of rates over the entire period, trends for mortality, case fatality, and incidence in the state of Santa Catarina are decreasing, decreasing, and stationary, respectively. In Paraná, rates over the entire period showed a stationary trend for mortality, decreasing for case fatality, and increasing for incidence. Conclusion: COVID-19 had a devastating effect on the states of Santa Catarina and Paraná. Both states experienced the progression of the COVID-19 pandemic, with higher case fatality and mortality rates observed in Paraná, while Santa Catarina had a higher incidence rate over the three years of the COVID-19 pandemic.