Medical Dictionary

H1N1

noun \ ˈāch-ˈwən-ˈen-ˈwən \

medical Definition of H1N1

1 : a virus that is a subtype (H1N1) of the orthomyxovirus (species Influenza A virus of the genus Influenzavirus A) causing influenza A, that infects birds, pigs, and humans, and that includes strains which may occur in seasonal epidemics or sometimes pandemics
  • … by the third week of April it was established that the illness resulted from a triple recombination of human, avian, and swine influenza viruses; the virus has been found to be H1N1.
  • —Lindsey R. Baden et al.The New England Journal of Medicine18 June 2009
  • Last year, older people had some immunity to the H1N1 virus because it resembled strains that circulated decades ago.
  • —Blythe BernhardThe St. Louis Post-Dispatch16 Jan. 2011
Note: The subtype H1N1 is distinguished by a mutation of hemagglutinin (H1) that affects the ability of the virus to infect cells, and a mutation of a neuraminidase (N1) that enables the release of the replicated virus from cells.
2 : influenza caused by the H1N1 virus; especially : swine flu
  • If you or your child came down with influenza during the H1N1, or swine flu, outbreak in 2009, it may not have happened the way you thought it did.
  • —Nicholas BakalarThe New York Times3 Feb. 2011
  • Thankfully, the H1N1 flu didn't turn into the doomsday bug that some scientists feared.
  • The Chicago Tribune17 Apr. 2010

Seen and Heard

What made you want to look up H1N1? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

of very fine texture or delicate form

Get Word of the Day daily email!

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!