Modeling Neisseria meningitidis transmission dynamics and the impact of pentavalent vaccination targeting serogroups A, C, W-135, Y, and X in the African meningitis belt

Abstract

The African meningitis belt (AMB) faces recurring epidemics of Neisseria meningitidis (Nm) (a bacterium that causes meningococcal meningitis), posing significant public health challenges. This study develops a Susceptible-Carrier-Infected-Recovered (SCIR)-based dynamic model to investigate Nm transmission dynamics in the AMB region, focussing on the impact of pentavalent meningococcal conjugate vaccines targeting serogroups A, C, W-135, Y, and X. By incoporating vaccination strategies into the model, we provide a comprehensive framework for evaluating vaccine effectiveness and informing outbreak prevention and control efforts. Our model stratifies the population into high-risk individuals (ages 1–29 years), who are the primary targets of vaccination campaigns, and low-risk individuals (all other age groups), capturing differences in susceptibility and vaccine coverage. Our results reveal that the introduction of pentavalent vaccines significantly reduces the prevalence of carriers, particularly among high-risk groups, thereby curbing transmission and mitigating epidemic risks across the AMB region. Key epidemiological parameters, including reproduction numbers (R₀), are derived to support targeted intervention strategies. Further analysis highlights the role of vaccination in lowering Nm transmissibility, especially in densely populated settings where close contact accelerates spread. Moreover, potential drivers of Nm outbreaks, including climate variability, socioeconomic disparities, and population density, are identified, highlighting the need for integrated public health intervention strategies. Further simulations also reveal the effectiveness of pentavalent vaccination among high-risk populations; however, further research is urgently needed to understand disease heterogeneity and vulnerability, particularly in young children and underserved communities. Thus, this study contribute to advancing our understanding of effective and sustainable vaccination strategies and enhancing epidemic preparedness in meningitis-endemic regions.