Malaria remains a major public health challenge for children under five years in sub-Saharan Africa. This paper develops an age structured SVIRSI compartmental model to simulate malaria transmission dynamics with RTS, S/AS01 vaccination as a control variable for children under five years in Bungoma County, Kenya. The model incorporates vaccination rate, vaccine efficacy, waning immunity, and mosquito control. The effective reproduction number Rₑ is derived via the next-generation matrix method. Positivity, boundedness, existence, uniqueness, local and global stability of the disease-free equilibrium are established. Sensitivity analysis identifies the most influential parameters. Bifurcation analysis reveals backward bifurcation. Numerical simulations using the fourth-order Runge-Kutta method confirm theoretical results. The computed Rₑ=0. 00157<1 indicates that the current vaccination programme is sufficient for malaria elimination.
Simiyu et al. (Mon,) studied this question.