Spatial and Trend Analysis of Meningococcal C Vaccination Coverage in Children Living in Brazil Between 2011 and 2021: an Ecological Study
Authors: Pereira Paula Luciana Gonçalves , Silva Thales Philipe Rodrigues da , Rodrigues Gilmar José Coelho , Ferraz Marcela Lencine , Ribeiro Elice Eliane Nobre , Silva Tércia Moreira Ribeiro da , Souza Maíza Diniz , Matozinhos Fernanda Penido 
Published: December 2022

Abstract
Background
Immunization is an important public health intervention worldwide, since it helps preventing, controlling, eradicating and reducing the number of death cases resulting from immunopreventable diseases. Meningococcal C conjugate vaccine (MenC) was made available for children under 2 years old due to significant increase in the number and rate of meningococcal disease (MD) serogroup C cases in Brazil, which recorded outbreaks in different regions. Identifying regions with low MenC vaccine application coverage is a priority strategy to target immunization actions, as well as to reduce the risk of DM circulation in different countries. Spatial analysis can help identifying areas with large numbers of children susceptible to MD, as well as directing priority health policies and strategies to these regions. The aim of the current study is to analyze meningococcal C vaccination coverage based on temporal trends in MenC vaccine coverage over 11 years, as well as the spatial distribution of MenC vaccine coverage, based on identifying spatial clusters with large numbers of children susceptible to MD.
Methods
This ecological, mixed study was conducted with secondary data about MenC vaccine coverage from 2011 to 2021, in Brazil, and made available by the National Immunization Program Information System (SI-PNI). This ecological, mixed study was conducted with secondary data about MenC vaccine coverage from 2011 to 2021, in Brazil, and made available by the National Immunization Program Information System (SI-PNI). Descriptive analysis was used to assess the annual coverage of MenC vaccine, based on geographic region, by taking into consideration all 26 Brazilian Federative Units (UF), the Federal District and the analyzed years. Prais-Winsten linear regression model was used for trend analysis purposes: MenC vaccination coverage per state, per Brazilian region (all five regions), and MenC vaccination coverage countrywide were used as dependent variables. Analyzed years were used as independent variable. Spatial dependence and incidence of spatial clusters formed by municipalities with high and low MenC vaccination coverage were assessed through spatial statistical analysis.
Results
In the current study have evidenced downward trend in MenC vaccination coverage in Brazil, in all five Brazilian regions and in 20 of the 27 Brazilian states, as well as progressive increase in the number of spatial clusters with low vaccination coverage, mainly in Northern and Northeastern Brazil.
Conclusion
These findings are expected to influence the formulation of practices, policies, programs and actions based on robust scientific evidence about the development of MD prevention and health promotion strategies and interventions, both at national and global level.