The struggle for space: Viral extinction through competition for cells

TL;DR

This paper explores how physical space constraints and host defenses can lead to the extinction of viral infections through competition for susceptible cells, highlighting the role of spatial limitations in infection dynamics.

Contribution

It introduces a mechanism where spatial constraints limit viral proliferation, leading to infection clearance, and discusses implications for controlling viral spread in tissues.

Findings

Physical space limits viral progeny advantage.

Host defenses can surpass a threshold to clear infection.

Spatial constraints influence infection propagation and control.

Abstract

The design of protocols to suppress the propagation of viral infections is an enduring enterprise, especially hindered by limited knowledge of the mechanisms through which extinction of infection propagation comes about. We here report on a mechanism causing extinction of a propagating infection due to intraspecific competition to infect susceptible hosts. Beneficial mutations allow the pathogen to increase the production of progeny, while the host cell is allowed to develop defenses against infection. When the number of susceptible cells is unlimited, a feedback runaway co-evolution between host resistance and progeny production occurs. However, physical space limits the advantage that the virus can obtain from increasing offspring numbers, thus infection clearance may result from an increase in host defenses beyond a finite threshold. Our results might be relevant to better understand propagation of viral infections in tissues with mobility constraints, and the implications that environments with different geometrical properties might have in devising control strategies.