Dr Anass Bouchnita
Title:
A genotype-structured epidemiological model to gain insights into the emergence and competition of variants
Abstract:
Genotype-structured models have been instrumental in unraveling the complexities of systems originating from ecology, immunology, and oncology. These models provide a continuous framework for integrating evolutionary mechanisms into population dynamics. Here, we introduce, for the first time, a phenotype-structured model applied to the study of infectious disease. It expands on previously developed susceptible-infected-recovered (SIR) model with population-immunity and describes virus evolution as a diffusion process. After calibrating the model, we apply it to show that a high basic reproduction rate, elevated mutation rate, broader cross-protection, and diminished genotypic distance are all factors that promote the emergence of variants. Moreover, we assess the impact of variant emergence based on the characteristics of the original and emerging variant, the robustness and broadness of population immunity, and the mutation rate. Our simulations underscore the necessity of broad cross-immunity for eradicating the original variant post-emergence of a more transmissible one. Furthermore, we demonstrate that robust, cross-variant immunity reduce the frequency of outbreaks driven by virus evolution and immune waning. This adaptable approach can be used to study a wide range of viruses and can be used to integrate genomic data into epidemiological modeling frameworks.