The evolution of human influenza viruses

Philos Trans R Soc Lond B Biol Sci. 2001 Dec 29;356(1416):1861-70. doi: 10.1098/rstb.2001.0999.

Abstract

The evolution of influenza viruses results in (i) recurrent annual epidemics of disease that are caused by progressive antigenic drift of influenza A and B viruses due to the mutability of the RNA genome and (ii) infrequent but severe pandemics caused by the emergence of novel influenza A subtypes to which the population has little immunity. The latter characteristic is a consequence of the wide antigenic diversity and peculiar host range of influenza A viruses and the ability of their segmented RNA genomes to undergo frequent genetic reassortment (recombination) during mixed infections. Contrasting features of the evolution of recently circulating influenza AH1N1, AH3N2 and B viruses include the rapid drift of AH3N2 viruses as a single lineage, the slow replacement of successive antigenic variants of AH1N1 viruses and the co-circulation over some 25 years of antigenically and genetically distinct lineages of influenza B viruses. Constant monitoring of changes in the circulating viruses is important for maintaining the efficacy of influenza vaccines in combating disease.

Publication types

  • Review

MeSH terms

  • Biological Evolution*
  • Humans
  • Influenza A virus / physiology*
  • Influenza B virus / physiology*
  • Phylogeny*
  • Recombination, Genetic