H1N2

H1N2 is a subtype of the species avian influenza virus(bird flu virus) currently endemic in both humanand pigpopulations.

H1N1, H1N2, and H3N2are the only known avian flu virus subtypes currently circulating among humans.

The new A(H1N2) strain appears to have resulted from the reassortmentof the genesof the currently circulating influenza A(H1N1) and A(H3N2) subtypes. The hemagglutininproteinof the A(H1N2) virus is similar to that of the currently circulating A(H1N1) viruses and the neuraminidaseproteinis similar to that of the current A(H3N2) viruses.

It is unknown where the A(H1N2) virus originated, but on February 62002, the World Health Organization(WHO) in Genevaand the Public Health Laboratory Service(PHLS) in the United Kingdomreported the identification influenza A(H1N2) virus from humans in England, Israel, and Egypt. In addition to the virus isolates reported by WHO and PHLS, the Centers for Disease Control and Preventionhas identified influenza A(H1N2) virus from patient specimens collected during the 2001-2002and 2002-2003seasons. Influenza A(H1N2) viruses have circulated transiently in the past. Between December 1988and March 1989, 19 influenza A(H1N2) virus isolates were identified in 6 cities in China, but the virus did not spread further.

The H1N2 virus is not very different from the currently circulating influenza viruses. The H1 protein of the H1N2 virus is like the H1 protein of the currently circulating H1N1 viruses and the N2 protein is similar to the N2 protein in the currently circulating H3N2 viruses. The difference is that we don't commonly see the H1 and N2 proteins on the same virus.

The A(H1N2) virus is not causing a more severe illness than other influenza viruses, and no unusual increases in influenza activity have been associated with the A(H1N2) virus. Because both the hemagglutinin and neuraminidase protein on the A(H1N2) virus closely matches the hemagglutinin and neuraminidase proteins of viruses included in the current influenza vaccine, the vaccine should provide good protection against influenza A(H1N2) virus as well as protection against the currently circulating A(H1N1), A(H3N2), and B viruses.

Sources

• Questions and Answers About Influenza A(H1N2) VirusesThis is the source of most of this article.
• Phylogenetic analysis of H1N2 isolates of influenza A virus from pigs in the United States
• CDC

This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/H1N2 Wikipedia article H1N2.