ABSTRACT
This chapter aims to construct some mathematical models containing different compartments while incorporating the factors of COVID-19 disease progression mechanisms to overcome the challenges of disease modelling to some extent. Coronavirus disease 2019, the highly infectious disease caused by severe acute respiratory syndrome coronavirus 2, has had a catastrophic effect on the world's demographics, resulting in more than 3.8 million deaths worldwide, emerging as the most consequential global health crisis. The COVID-19 virus spreads primarily through droplets of saliva or discharge from the nose, which enter a person's body through various contact routes such as mouth, eyes, or nose, causing a mild to moderate respiratory illness, like the common cold, which includes dry cough, fever, sore throat, loss of sense of smell and taste, headache, shortness of breath, and so on, while developing serious illness or even death in cases of older people and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease, and cancer.
