2021/04/27 by L. Vanel, Vanel, L.
Biochemistry, Genetics and Molecular Biology · Mathematics · Medicine · #COVID-19 epidemiological studies #Chemical Physics (physics.chem-ph) #Evolution and Genetic Dynamics #FOS: Physical sciences #Mathematical and Theoretical Epidemiology and Ecology Models
paper · pdf · doi:10.48550/arxiv.2104.13357
openalex publication_date 2021/04/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The shape of an epidemic wave in simple epidemic models applies to a homogeneous distribution of infected people in the population. In large inhomogeneous systems, at country-scale for instance, the wave shape is similar except for the short time behavior. For such cases, we show that the full wave shape is tied to an exponential decay. Using out-of-equilibrium thermodynamics, we build a model in which this decay results from an increase in entropy until reaching a stable infected population fraction. We find that the elementary probability of being infected determines this fraction, leading to a thermodynamic criterion for herd immunity and epidemic outbreaks.