A new class of COVID-19 compartmental models that explicitly incorporates the changes in population-immunity

The COVID-19 landscape has been rapidly changing during the last few months. Several new effects have been influencing COVID-19 transmissibility and severity such as waning immunity, vaccination, emerging variants of concern. As a result, mathematical models that describe COVID-19 transmission dynamics are becoming very complex, highly-dimensional and computationally expensive. In this talk, we will introduce a new class of COVID-19 epidemiological models that explicitly describe the changes in the population-immunity and their effects on COVID-19 transmissibility and severity. We begin by presenting the derivation of the model from a more complex multiscale immuno-epidemiological model. Then, we discuss how this new class of models allows the integration of vaccination and immune waning in a simple and meaningful way, by applying it to determine the optimal timing for switching from primary vaccination of the younger population to giving additional doses to high risk groups. Finally, we show how this new modeling technique was used to accurately estimate the impact of Omicron emergence in the US. References: 1. Bouchnita, Anass, et al. "COVID-19 Scenario Projections: The Emergence of Omicron in the US-January 2022." (2022).