Effects of vaccination on mitigating COVID-19 outbreaks : a conceptual modeling approach

Abstract

This paper is devoted to investigating the impact of vaccination on mitigating COVID-19 outbreaks. In this work, we propose a compartmental epidemic ordinary differential equation model, which extends the previous so-called SEIRD model [1–4] by incorporating the birth and death of the population, disease-induced mortality and waning immunity, and adding a vaccinated compartment to account for vaccination. Firstly, we perform a mathematical analysis for this model in a special case where the disease transmission is homogeneous and vaccination program is periodic in time. In particular, we define the basic reproduction number R0 for this system and establish a threshold type of result on the global dynamics in terms of R0. Secondly, we fit our model into multiple COVID-19 waves in four locations including Hong Kong, Singapore, Japan, and South Korea and then forecast the trend of COVID-19 by the end of 2022. Finally, we study the effects of vaccination again the ongoing pandemic by numerically computing the basic reproduction number R0 under different vaccination programs. Our findings indicate that the fourth dose among the high-risk group is likely needed by the end of the year. © 2023 the Author(s), licensee AIMS Press.