A fractional-order model of COVID-19 and human Metapneumovirus co-dynamics: a Laplace-Adomian decomposition approach for epidemiological prediction and intervention analysis

The co-dynamics of COVID-19 and human Metapneumovirus (HMPV) pose a public health threat that can be caused by severe respiratory illness in vulnerable groups such as the elderly, children, and immune-weakened individuals. In this study, we present a mathematical model with the Caputo fractional derivative and use a semi-analytical Laplace-Adomian decomposition method (LADM) to obtain the approximate solutions and simulate the co-dynamics of two respiratory pathogens. The results are validated with real COVID-19 data for Bangladesh, revealing that the fractional-order model demonstrates optimal agreement at α =0.83 . The analysis highlights the impact of fractional-order dynamics on transmission rates, quarantine efficacy, and recovery trajectories. The study advances by integrating memory effects and providing a framework for evaluating intervention strategies. The results of this study suggest that the fractional-order model provides a more flexible framework with memory effects for multiple respiratory disease outbreaks.