Relationship Between Vaccination Coverage and Cases of Bacterial Meningitis in Children Under 10 Years in Sobral-Ce (2018–2023)

The decline in childhood vaccination coverage in Brazil has been associated with the resurgence of vaccine-preventable diseases such as bacterial meningitis. In municipalities such as Sobral (CE), this trend raises concerns about increasing disease incidence in children. Thus, this study aimed to evaluate the evolution of childhood vaccination coverage and its possible association with the incidence of bacterial meningitis in children under 10 years in Sobral between 2018 and 2023. Ecological time-series study based on secondary data extracted from SINAN (TabNet/DataSUS) and the National Immunization Program Information System (SI-PNI). Confirmed cases of bacterial meningitis in children under 10 years living in Sobral between 2018 and 2023 were included, considering vaccination coverage of pentavalent, pneumococcal and meningococcal C vaccines between 2018 and 2022. A decline in vaccination coverage was observed from 2019 onwards, especially for pentavalent (80.67%), pneumococcal (92.44%) and meningococcal C (90.65%) vaccines, with an average reduction of approximately 8% compared with 2018 levels. In 2020, a slight recovery was seen: pentavalent (89.92%), meningococcal C (91.86%) and pneumococcal (95.19%). However, in 2021, all coverages fell again, remaining below 90%, with the lowest values for MenC (87.61%) and pneumococcal (88.96%), and remained at similar levels in 2022. During the same period, 81 cases of bacterial meningitis were recorded in children under 10 years: 17 in 2018, 25 in 2019, 4 in 2020, 1 in 2021, 6 in 2022 and 8 in 2023. In 2019, a possible association was observed between reduced childhood vaccination coverage and increased bacterial meningitis cases in children under 10 years in Sobral. In subsequent years (2020–2021), despite coverage remaining below ideal levels, there was a marked decrease in notifications, which may be related to underreporting during the COVID-19 pandemic. In 2022 and 2023, both coverage rates and case numbers remained relatively stable. These findings reinforce the importance of strengthening epidemiological surveillance and restoring high vaccination coverage as strategies for preventing bacterial meningitis in childhood.