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Molecular evolution of human influenza A/H3N2 virus in Asia and Europe from 2001 to 2003

X Sherry Chi1, Trentice V Bolar, Ping Zhao

  • 1Applied Immunology and Microbiology Division, Wyeth Vaccines Research, 401 N. Middletown Road, Building 180, Pearl River, NY 10965, USA.

Journal of Clinical Microbiology
|December 8, 2005
PubMed

Insights

Four amino acid substitutions in influenza A/H3N2 hemagglutinin sequences caused antigenic drift. This analysis of human influenza strains from 2001-2003 reveals the evolution from A/Panama/2007/99-like to A/Fujian/411/2002-like strains.

Area of Science:

  • Virology
  • Molecular Biology
  • Epidemiology

Background:

  • Influenza A/H3N2 viruses undergo continuous antigenic variation.
  • Monitoring hemagglutinin (HA) evolution is crucial for understanding influenza epidemiology.

Purpose of the Study:

  • To analyze amino acid substitutions in HA sequences of human influenza A/H3N2 strains.
  • To identify genetic changes responsible for antigenic drift between 2001 and 2003.

Main Methods:

  • DNA sequencing of hemagglutinin genes from 146 influenza A/H3N2 strains.
  • Analysis of strains collected from respiratory specimens in Asia and Europe (2001-2003).

Main Results:

  • Identified four key amino acid substitutions: L25I, H75Q, H155T, and Q156H.
  • These substitutions correlate with the antigenic shift from A/Panama/2007/99-like to A/Fujian/411/2002-like strains.

Conclusions:

  • Specific amino acid changes in HA drive antigenic evolution of influenza A/H3N2.
  • Understanding these mutations aids in predicting future influenza strain characteristics and vaccine efficacy.

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