Epidemiological theory of virus variants

TL;DR

This paper introduces a physical theory based on scale invariance and fixed points to model the evolution of competing virus variants, validated with COVID-19 data.

Contribution

It develops a novel theoretical framework using epidemic Renormalization Group concepts to describe virus variant dynamics.

Findings

Theory captures large time scale invariance in virus evolution

Model aligns well with empirical COVID-19 variant data

Provides a new perspective on competing variants dynamics

Abstract

We propose a physical theory underlying the temporal evolution of competing virus variants that relies on the existence of (quasi) fixed points capturing the large time scale invariance of the dynamics. To motivate our result we first modify the time-honoured compartmental models of the SIR type to account for the existence of competing variants and then show how their evolution can be naturally re-phrased in terms of flow equations ending at quasi fixed points. As the natural next step we employ (near) scale invariance to organise the time evolution of the competing variants within the effective description of the epidemic Renormalization Group framework. We test the resulting theory against the time evolution of COVID-19 virus variants that validate the theory empirically.