VACCINATION COVERAGE WITH DTPA IN PREGNANT WOMEN AND PENTAVALENT VACCINE: CORRELATION WITH CASES OF PERTUSSIS IN CHILDREN UNDER ONE YEAR OF AGE IN BRAZIL (2014–2024)

Pertussis is an acute respiratory infection that can be potentially severe in infants under one year of age, especially in the first six months of life. As a preventive measure, the dTpa (adult-type acellular diphtheria-tetanus-pertussis) vaccine was incorporated into the Brazilian vaccination schedule for pregnant women in 2014, complementing the protection provided by the pentavalent vaccine in childhood. Thus, analysis of vaccination coverage (VC) of these vaccines and its relationship with pertussis cases in children under one year may indicate the effectiveness of these strategies. To evaluate VC of dTpa in pregnant women and pentavalent vaccine, and its correlation with confirmed pertussis cases in children under one year in Brazil, between 2014 and 2024. Retrospective ecological study with time-series analysis using secondary data from DATASUS and the vaccination coverage panels of the Ministério da Saúde. Annual VCs of dTpa in pregnant women and pentavalent vaccine, as well as confirmed pertussis cases in children under one year between 2014 and 2024 in Brazil, were analyzed. Trends were described comparatively. During the study period, dTpa coverage in pregnant women increased from 9.34% (2014) to 86.28% (2024), but with oscillations, including a 20.12% decline between 2019 and 2021. dTpa coverage in pregnant women did not reach 95% in any year analyzed. Pentavalent coverage showed a downward trend after 2015 (96.3%), reaching its lowest value in 2019 (70.76%), but recovered in recent years (87.32% in 2023 and 89.97% in 2024). Finally, pertussis cases in children under one year declined significantly from 2014 (5,033 cases) to 2023 (124 cases). However, an increase was observed in 2024 (1,227 cases), the third highest number in the period. There is a gradual improvement in dTpa coverage in pregnant women and recent recovery of pentavalent coverage after a period of decline. The overall reduction in pertussis cases in children under one year suggests a positive impact of vaccination in the target groups, although the recent increase in 2024 highlights the importance of maintaining high coverage and continuous immunization strategies to prevent new outbreaks.