Impact of Meningococcal C Conjugate Vaccine on Incidence of Invasive Meningococcal Disease in an 18-Year Time Series in Brazil and in Distinct Brazilian Regions.

Objective To evaluate the impact of meningococcal C conjugate (MCC) vaccine in Brazil. Methods Ecological study assessing all invasive meningococcal disease (IMD) and meningococcal C disease (MenC) cases reported in all age groups, from 2001 to 2019. MCC was implemented in 2010. Data were collected on the DATASUS platform. Joinpoint regression was performed to assess the annual percent change (APC) of the incidence rate. Results Invasive meningococcal disease incidence decreased in all Brazilian regions from 2001 onwards, without apparent additional reduction attributable to MCC vaccine in the North, Northeast and South. The higher and statistically significant APC reduction in all age groups, in the North and South, and in children <5 years, in the Northeast, occurred between 2001 and 2011 (-15.4%), 2004 and 2012 (-14.4%), and 2001 and 2013 (-10.3%), respectively, before MCC vaccine implementation. Annual incidence of MenC in children under 5 years significantly fell in the North (-6.8%; 2011-2018), Southeast (-40.6%; 2010-2015) and Midwest (-48.6%; 2010-2014), which may be attributable to MCC implementation. Conclusion Invasive meningococcal disease and MenC behaved differently after MCC vaccine implementation in Brazil during this 18-year time-series analysis. This suggests that the control of IMD should be based on multiple public health care measures and considered on a regional basis.