Mlyashimbi, Helikumi; Massawe, Estomih S.; Makinde, Oluwole D.
Description:
In this paper, a mathematical model of infectious diseases by immigrants in a vaccinated and temporary
immune protected population has been investigated. The model incorporates the assumption that
immigrant individuals enter in the respective population with an immunity received from either
vaccination or recover from the disease. The stability of the system has been analyzed for the existence
of the disease-free and endemic equilibrium points, and it has been shown that the disease free
equilibrium point is asymptotically stable when an effective reproduction number is less than unity and
unstable when an effective reproduction number is greater than unity. From the analysis of the model, it
is shown that vaccination coverage is greater than the vaccination; otherwise the disease will persist
within the community. It is also shown that the increase of immigrants in a population tends to lower
the first dose-vaccination coverage, hence the disease become endemic in the population. Numerical
simulations of the model showed that in the absence of the immigrants, the disease can be eradicated
in a population with a single-dose vaccination only.