Modeling adenovirus transmission dynamics using a SEVAIR framework with asymptomatic and vaccinated classes

In this work, we extended the classical Susceptible–Exposed–Vaccinated–Infected–Recovered (SEVIR) framework by incorporating an asymptomatic class, leading to the formulation of a new Susceptible–Exposed–Vaccinated–Asymptomatic–Infected–Recovered (SEVAIR) model that more accurately reflects the transmission characteristics of adenovirus. To account for memory effects and capture complex temporal behavior, the model was developed using the fractal-fractional Caputo-Fabrizio derivative with a power-law kernel. Existence and stability of solutions based on fixed point theory and Hyers-Ulam stability criteria were derived. Both the disease-free and endemic equilibrium states were derived, and their local stability properties were examined. Additionally, the basic reproduction number was computed to understand the disease's spread threshold. The theoretical results were supported by numerical simulations, which were performed using a modified Adams-Bashforth approach tailored for the fractional framework.