DYNAMIC ANALYSIS OF VACCINATION WITH FRACTIONAL-DOSE MENINGOCOCCAL VACCINE IN THE AFRICAN MENINGITIS BELT

To research the potential impact of fractional dosing of multivalent conjugate meningococcal vaccine in the African meningitis belt, we formulate a periodic compartmental differential equation model with a latency in asymptomatic carriers. We derive the reproductive ratio [Formula: see text] of the periodic functional differential system and further show that [Formula: see text] is the parameter that determines both global extinction and uniform persistence of meningococcal meningitis, namely, the unique disease-free equilibrium of the system is a global attractor and the meningococcal meningitis is gradually disappearing when [Formula: see text] is less than [Formula: see text]; and when [Formula: see text] is greater than [Formula: see text], a positive periodic solution exists and the meningococcal meningitis persists consistently. Numerically, we use data from Dori, a town in Burkina Faso, to parameterize the model and simulate how solutions will behave over time. We also carry out numerical computation results for [Formula: see text] as the output parameter with respect to related parameters of a fractional-dose conjugate vaccine targeting the bacterium Neisseria meningitidis serotypes A, C, Y and W (ACYW). The study provides scientific suggestions for effectively using fractional-dose multivalent conjugate meningococcal vaccines in the belt when the vaccine stockpiles are insufficient.