COVID-19 mortality in Brazil in different age groups: differentials between extreme rates in 2021 and 2022

Abstract

This ecological study evaluated the trajectory of COVID-19 mortality rates in Brazil and compared the extreme rates of 2022 and 2021, in different age groups. Data on deaths due to severe acute respiratory syndrome by COVID-19 were obtained from the Influenza Epidemiological Surveillance Information System. Deaths were evaluated from January 10, 2021 to February 12, 2022, grouped into Epidemiological Weeks (EW). Data analysis was conducted in the R software, using Poisson models to estimate mortality rates. Statistical significance level was set at 5%. A total of 408,180 deaths were evaluated, 0.34% of whom were under 18 years old, and 64.6% of whom were 60 years old and over. On the one hand, in the 0-1, 2-4 and 5-11 age groups, higher mortality rates were observed in EW 4-6/2022, compared to the higher ones in 2021. On the other, in the 12-17 age group, a lower rate was estimated in the EW 4-6/2022 group compared to the EW 11-13 group in 2021, with a mortality ratio of 0.60 (95%CI: 0.38-0.94). Opposing patterns were detected in COVID-19 mortality in Brazil among children and individuals included in the national vaccination campaign. Among the former, mortality rates equal to or worse than in previous phases of the epidemic were observed, contrasting with the consistent and strong decline registered in the latter, reinforcing the effectiveness of COVID-19 vaccines.