Genetic Structure of Human A/H1N1 and A/H3N2 Influenza Virus on Corsica Island: Phylogenetic Analysis and Vaccine Strain Match, 2006–2010
2011

Genetic Analysis of Influenza A Viruses on Corsica Island (2006–2010)

Sample size: 371 publication Evidence: moderate

Author Information

Author(s): Alessandra Falchi, Jean Pierre Amoros, Christophe Arena, Jean Arrighi, François Casabianca, Laurent Andreoletti, Clément Turbelin, Antoine Flahault, Thierry Blanchon, Thomas Hanslik, Laurent Varesi, Malcolm Gracie Semple

Primary Institution: INSERM, UMR-S 707, Paris, France

Hypothesis

The study aims to analyze the genetic patterns of Hemagglutinin (HA) genes of influenza A strains circulating on Corsica Island during the 2006–2009 epidemic seasons and the 2009–2010 pandemic season.

Conclusion

The molecular analysis showed that each season had a dominant lineage characterized by at least one fixed mutation, with A/H3N2 and A/H1N1pdm isolates showing multiple fixations at antigenic sites.

Supporting Evidence

  • The study analyzed 371 samples collected from patients with influenza-like illness.
  • Phylogenetic analysis revealed that A/H3N2 strains were closely related to WHO recommended vaccine strains.
  • A/H1N1 strains showed significant mutations that could affect vaccine efficacy.
  • Vaccine effectiveness varied across seasons, being higher for A/H1N1 compared to A/H3N2.

Takeaway

Researchers looked at flu viruses on Corsica Island over four years to see how they changed and matched with vaccines, finding that some viruses had special mutations that helped them survive.

Methodology

Nasopharyngeal samples from 371 patients with influenza-like illness were collected and analyzed using RT-PCR and phylogenetic analysis.

Limitations

The study did not analyze genetic evolution outside HA proteins and relied on the sensitivity of molecular techniques for strain identification.

Participant Demographics

Patients with influenza-like illness from Corsica Island.

Digital Object Identifier (DOI)

10.1371/journal.pone.0024471

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