Role of concurrent evolution in antigenic and non-antigenic traits in viral endemicity

Determine how simultaneous evolution in antigenic traits (immune escape through changes in antigenic position) and non-antigenic traits (such as inter-host transmissibility) governs whether rapidly evolving viruses achieve endemicity in host populations, in order to identify the eco-evolutionary constraints enabling the transition from epidemic to endemic phases.

Background

The paper introduces a minimal eco-evolutionary framework extending the classical SIR model to allow for evolution in both transmissibility and antigenic position. Prior work has often examined antigenic escape and transmissibility evolution separately, but empirical evidence (e.g., SARS-CoV-2) suggests both pathways operate concurrently and influence epidemic trajectories.

The authors note that while individual mechanisms are well studied, the combined effect on endemicity is not yet understood. Their simulations reveal non-trivial interactions, including accelerated early transmissibility evolution and later antigenic diversification, motivating a precise understanding of how these coupled evolutionary processes determine viral persistence.