Analysis of Trends in Immunization Coverage Inequalities Among Children Aged 12–23 Months in Guinea: Data from Demographic and Health Surveys in 2005, 2012, and 2018

Background: The aim of this study was to describe trends in inequalities in full immunization of children aged 12 to 23 months and to identify associated socioeconomic factors. Methods: A secondary analysis was carried out using data from three Demographic and Health Surveys (DHS) conducted in 2005, 2012 and 2018 in the Republic of Guinea. The concentration, or Lorenz curve, and associated index were used to measure inequalities over time. Multivariate logistic regression was employed to identify socioeconomic factors associated with full vaccination of children aged 12 to 23 months. Results: The study found a strongly positive overall concentration index (CI > 0.5) for complete vaccination of children aged 12 to 23 months, indicating inequalities in favor of wealthier households. This inequality decreased in 2012 but increased again in 2018. Children from wealthy families were nearly twice as likely to be fully vaccinated compared to children from very poor families (adjusted OR 1.79, 95% CI: 1.38 - 2.32). Conclusion: This study revealed significant inequalities favoring wealthy families in the use of immunization services by children aged 12 to 23 months in Guinea. It also underscores the need for planning and implementing strategies to reduce these inequalities in access to and use of immunization services.