PROFILE OF INFLUENZA HOSPITALIZATIONS AND CORRELATION WITH VACCINATION COVERAGE IN BRAZIL: AN ECOLOGICAL STUDY FROM 2020 TO 2024

Influenza is a viral respiratory infection with the potential to cause seasonal outbreaks and severe complications, especially in vulnerable groups such as older adults and children. The reduction in vaccination coverage rates in Brazil is a warning sign for the health system. This study aims to analyze the profile of hospitalizations due to Influenza between 2020 and 2024. Ecological, quantitative study based on secondary data from the TABNET/DATASUS platform. Information on Influenza was included for the different regions of Brazil, considering variables such as sex and age group (SINAN data), as well as the number of hospitalizations and deaths (SIH/SUS data) between 2020 and 2024. Vaccination coverage indicators from the Ministry of Health were also used. Descriptive statistics were applied using Excel for organizing the results. During the period analyzed, a total of 135,960 hospitalizations due to Influenza were observed in Brazil, with 66,924 (49.2%) patients male and 69,036 (50.7%) female. Among all cases, there were 7,013 deaths, corresponding to 5.1%. The region with the highest number of hospitalizations was the Northeast, with 59,788 (43.9%) notifications, and the Southeast showed the highest number of deaths regardless of age group, with 2,624 deaths, corresponding to 37.4% of all Influenza deaths from 2020 to 2024. The least affected region was the Center-West, with just over 9,000 cases and 576 deaths. Regarding age group, children aged 1 to 4 years and older adults aged 80 years or more were the most affected, with 20,966 and 16,934 hospitalizations, respectively. Despite being the second most prevalent age group, older adults aged 80 years or more accounted for the highest number of deaths (2,796). In addition, Influenza vaccination coverage in the older population has dropped drastically from 70.1% in 2021 to 40.45% in the North and 48.81% in the other regions of the country in 2024. According to Gonçalves et al. (2023), physiological changes, comorbidities and greater susceptibility to secondary infections make older adults more vulnerable to severe infectious conditions. Therefore, the relevance of annual Influenza vaccination, included in the Brazilian immunization schedule since 1999, is highlighted, especially in the autumn and winter, when incidence is higher.