Evolution and adaptation of the pandemic A/H1N1 2009 influenza virus
Mariette F Ducatez, Thomas P Fabrizio, Richard J Webby
Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
Abstract: The emergence of the 2009 H1N1 pandemic influenza virus [A(H1N1)pdm09] has provided the public health community with many challenges, but also the scientific community with an opportunity to monitor closely its evolution through the processes of drift and shift. To date, and despite having circulated in humans for nearly two years, little antigenic variation has been observed in the A(H1N1)pdm09 viruses. However, as the A(H1N1)pdm09 virus continues to circulate and the immunologic pressure within the human population increases, future antigenic change is almost a certainty. Several coinfections of A(H1N1)pdm09 and seasonal A(H1N1) or A(H3N2) viruses have been observed, but no reassortant viruses have been described in humans, suggesting a lack of fitness of reassortant viruses or a lack of opportunities for interaction of different viral lineages. In contrast, multiple reassortment events have been detected in swine populations between A(H1N1) pdm09 and other endemic swine viruses. Somewhat surprisingly, many of the well characterized influenza virus virulence markers appear to have limited impact on the phenotype of the A(H1N1)pdm09 viruses when they have been introduced into mutant viruses in laboratory settings. As such, it is unclear what the evolutionary path of the pandemic virus will be, but the monitoring of any changes in the circulating viruses will remain a global public and animal health priority.
Keywords: influenza, pandemic, evolution, adaptation
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.Download Article [PDF]