Spatially structured models of viral dynamics: a scoping review

SUMMARYThere is growing recognition in both the experimental and modeling literature of the importance of spatial structure to the dynamics of viral infections within the host. Aided by the evolution of computing power and motivated by recent biological insights, there has been an explosion of new, spatially explicit models for within-host viral dynamics in recent years. This development has only been accelerated in the wake of the COVID-19 pandemic. Spatially structured models offer improved biological realism and can account for dynamics that cannot be well-described by conventional, mean-field approaches. However, despite their growing popularity, spatially structured models of viral dynamics are underused in biological applications. One major obstacle to the wider application of such models is the huge variety in approaches taken, with little consensus as to which features should be included and how they should be implemented for a given biological context. Previous reviews of the field have focused on specific modeling frameworks or on models for particular viral species. Here, we instead apply a scoping review approach to the literature of spatially structured viral dynamics models as a whole to provide an exhaustive update of the state of the field. Our analysis is structured along two axes, methodology and viral species, in order to examine the breadth of techniques used and the requirements of different biological applications. We then discuss the contributions of mathematical and computational modeling to our understanding of key spatially structured aspects of viral dynamics and suggest key themes for future model development to improve robustness and biological utility.