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Swine influenza

H1N1 Virus Mutates into Relenza-Resistant Form in Lab Study

Strategic Insights

— 1 min read

Australian researchers at the North Melbourne WHO Collaborating Centre for Reference and Research on Influenza have discovered that the H1N1 flu virus has mutated into a form resistant to the antiviral drug Relenza. Although the mutation poses little threat to humans, the discovery highlights the potential for antiviral-resistant viruses to spread rapidly and travel widely around the world. The study's findings emphasize the need for continued vigilance and research into the effects of antiviral resistance on flu outbreaks.

Key Takeaways:

  • Researchers at the North Melbourne WHO Collaborating Centre for Reference and Research on Influenza discovered that 9 out of 391 influenza A(H1N1) viruses found in humans in Australasia and South-East Asia between 2006 and 2008 had a mutation that made them 300 times more resistant to zanamivir (sold as Relenza).
  • The mutation was not found when the specimens were taken from patients, but rather when the viruses multiplied in the lab.
  • Dr. Ian Barr, one of the researchers involved, stated that "That could mean there were very low levels of this mutation in the patient," suggesting that the mutation is not necessarily a clinical problem.
  • The recent spread of Tamiflu-resistant A(H1N1) viruses has shown that antiviral-resistant viruses can spread rapidly and travel widely around the world.
  • There are no known strains of Relenza-resistant influenza in humans, but a total of six cases of Tamiflu-resistant swine flu have been identified worldwide.
  • Biota, the developer of Relenza, downplayed the significance of the discovery, stating that "it's an in vitro discovery and there's no evidence that this mutation has infected patients."
  • GlaxoSmithKline (GSK), the manufacturer of Relenza, noted that "the clinical significance is yet to be determined."

Statistics:

  • 391 influenza A(H1N1) viruses found in humans in Australasia and South-East Asia between 2006 and 2008 were analyzed in the study.
  • 9 out of the 391 viruses had a mutation that made them 300 times more resistant to zanamivir (Relenza).
  • The mutation was not found when the specimens were taken from patients, but was discovered when the viruses multiplied in the lab.

Sources:

  • Journal of Virology
  • WHO Collaborating Centre for Reference and Research on Influenza
  • Biota
  • GlaxoSmithKline (GSK)

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