A Virologist’s Perspective on Influenza A(H1N1)

May 6 2009



That is the title of an article we'll be citing in our May 2009 Articles report, but we thought it important and timely to call your attention to it now.



Viruses are extremely adept at what scientists call "immune evasion" or the ability to mutate as a means of avoiding the effects of vaccines, which is why people can get sick with the flu more than once and why new vaccines are developed each year.  



Virologist and influenza expert Robert A. Lamb explains that the influenza A(H1N1) is a “complicated reassortant, containing a mixture of genes from influenza viruses that infect Eurasian swine, American swine, birds and humans.”



Lamb describes how the virus mutates, making it difficult to offer protection and contain outbreaks.

H1N1 belongs to the H1 influenza A virus family, which is one of 16 subtypes, based on the distinct structure of hemagglutinin (HA), one of the key influenza surface proteins.



Influenza viruses are further distinguished by the shapes of their neuraminidase (NA) proteins, of which there are 9 subtypes.



HA and NA proteins dot the surface of the virus particle like a protective "coat." When the virus mutates, it essentially "changes coats," altering the shape of its exterior surface and becoming unrecognizable to the human (or animal) immune system.

Category: Need to Know
Filed under: Flu, Infectious Diseases