TEMPORAL DISTRIBUTION OF HEPATITIS B VACCINATION COVERAGE IN NEWBORNS AND HEPATITIS B-RELATED HOSPITALIZATIONS IN CHILDREN UP TO 5 YEARS OF AGE (2018–2022)

Hepatitis B is a viral infection that can progress to severe chronic forms and is responsible for a high global burden of morbidity and mortality. In 2022, according to WHO estimates, there were 1.3 million deaths from viral hepatitis, 83% of which were attributed to hepatitis B virus (HBV). In Brazil, the hepatitis B vaccine has been available since 1998 in the Programa Nacional de Imunizações, with recommendation for administration within the first 24 hours of life. This study aimed to analyze hepatitis B vaccination coverage in newborns and the number of hospitalizations for acute hepatitis B in children under five years of age in Brazil. Observational, ecological and retrospective study based on secondary data extracted from SIH/SUS and SI-PNI, available in DATASUS. Data on newborns vaccinated against hepatitis B within 30 days of life and children up to five years hospitalized for acute hepatitis B (ICD-10: B16) from 2019 to 2022 were included. Vaccination coverage was collected annually, and temporal trends in hospitalizations were assessed by simple linear regression. No association tests between variables were performed, as the objective was descriptive and exploratory. A drop in vaccination coverage was observed in 2020 (65.77%) and 2021 (67.03%), followed by recovery in 2022 (82.76%). In parallel, hospitalizations for acute hepatitis B in children under five increased from 19 cases in 2019 to 29 in 2022. Linear regression indicated an upward trend, with a slope of 4.0 and a coefficient of determination R² = 0.77, suggesting that 77% of the variation in hospitalizations can be explained by temporal progression. Although no inferential analysis was conducted between variables, there is evident temporal coincidence between lower vaccination coverage and increased hospitalizations. The data suggest a temporal association between decreased vaccination coverage in newborns and increased hospitalizations for acute hepatitis B in children under five in Brazil. The impact of the COVID-19 pandemic on routine vaccination services may have contributed to reduced coverage in this period. Maintaining universal vaccination, particularly within the first 24 hours of life, should remain a continuous priority in public policies.