The impact of cross-immunity, mutation and stochastic extinction on pathogen diversity

Laith Aburaddad, Neil M. Ferguson

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

We examine the dynamics of antigenically diverse infectious agents using a mathematical model describing the transmission dynamics of arbitrary numbers of pathogen strains, interacting via cross-immunity, and in the presence of mutations generating new strains and stochastic extinctions of existing ones. Equilibrium dynamics fall into three classes depending on cross-immunity, transmissibility and host population size: systems where global extinction is likely, stable single-strain persistence, and multiple-strain persistence with stable diversity. Where multi-strain dynamics are stable, a diversity threshold region separates a low-prevalence, low-diversity region of parameter space from a high-diversity, high-prevalence region. The location of the threshold region is determined by the reproduction number of the pathogen and the intensity of cross-immunity, with the sharpness of the transition being determined by the manner in which immunity accrues with repeated infections. Host population size and cross-immunity are found to be the most decisive factors in determining pathogen diversity. While the model framework developed is simplified, we show that it can capture essential aspects of the complex evolutionary dynamics of pathogens such as influenza.

Original languageEnglish
Pages (from-to)2431-2438
Number of pages8
JournalProceedings of the Royal Society B: Biological Sciences
Volume271
Issue number1556
DOIs
Publication statusPublished - 7 Dec 2004
Externally publishedYes

Fingerprint

cross immunity
Pathogens
immunity
mutation
Immunity
extinction
pathogen
Mutation
pathogens
Population Density
population size
persistence
influenza
Human Influenza
Reproduction
Theoretical Models
mathematical models
Mathematical models
Infection
infection

Keywords

  • Antigenic variation
  • Cross-immunity
  • Infectious disease
  • Mathematical model
  • Population dynamics

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Agricultural and Biological Sciences (miscellaneous)

Cite this

The impact of cross-immunity, mutation and stochastic extinction on pathogen diversity. / Aburaddad, Laith; Ferguson, Neil M.

In: Proceedings of the Royal Society B: Biological Sciences, Vol. 271, No. 1556, 07.12.2004, p. 2431-2438.

Research output: Contribution to journalArticle

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