Mutation induced infection waves in diseases like COVID-19

TL;DR

This paper models how mutations in infectious diseases like COVID-19 can lead to rapid, large-scale infection waves, emphasizing the importance of vaccination speed and policy measures to prevent mutation-driven outbreaks.

Contribution

It generalizes the susceptible-infected-recovered model to include mutations, predicting super-exponential growth and complex wave patterns caused by mutation-infection feedback loops.

Findings

Mutations can cause super-exponential infection growth.

Infection waves can be revived by mutations if vaccination is slow.

Large infection waves may involve most of the population.

Abstract

After more than 6 million deaths worldwide, the ongoing vaccination to conquer the COVID-19 disease is now competing with the emergence of increasingly contagious mutations, repeatedly supplanting earlier strains. Following the near-absence of historical examples of the long-time evolution of infectious diseases under similar circumstances, models are crucial to exemplify possible scenarios. Accordingly, in the present work we systematically generalize the popular susceptible-infected-recovered model to account for mutations leading to repeatedly occurring new strains, which we coarse grain based on tools from statistical mechanics to derive a model predicting the most likely outcomes. The model predicts that mutations can induce a super-exponential growth of infection numbers at early times, which self-amplify to giant infection waves which are caused by a positive feedback loop between infection numbers and mutations and lead to a simultaneous infection of the majority of the population. At later stage -- if vaccination progresses too slowly -- mutations can interrupt an ongoing decrease of infection numbers and can cause infection revivals which occur as single waves or even as whole wave trains featuring alternative periods of decreasing and increasing infection numbers. This panorama of possible mutation-induced scenarios should be tested in more detailed models to explore their concrete significance for specific infectious diseases. Further, our results might be useful for discussions regarding the importance of a release of vaccine-patents to reduce the risk of mutation-induced infection revivals but also to coordinate the release of measures following a downwards trend of infection numbers.