Genetics of the 2009 Swine Flu
In the case of the 2009 flu, as infections spread throughout North America and around the world, researchers in affected countries isolated many samples of the virus. The U.S. Centers for Disease Control (CDC) analyzed these samples and concluded that all the new swine flu infections around the world were caused by the same strain. The genes from all the samples are "99 to 100% identical" (Seppa 2009).
The Variable Influenza A Genes
The popular media often describe influenza genes as coming from humans, birds, or pigs. However, they are not actual genes from these creatures — they are influenza virus genes from strains that evolved in those creatures. The Influenza A virus has eight genes, designated HA, NA, NP, NS, PB1, PB2, PA, and M.
Swine Flu Facts: Where Did The Virus Really Come From?
With various media sources contradicting each other, what is the truth about the 2009 swine flu’s genetic origin? According to an article in the New England Journal of Medicine, CNN and "Wired Science" are both right.
At right: Origin of each of the eight A/California/04/2009 (H1N1) genes, according to a report in the NEJM.
- "Emergence of a Novel Swine-Origin Influenza A (H1N1) Virus in Humans." Report from the Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team. New England Journal of Medicine, published online May 7, 2009.
- Brandon Keim. "Swine Flu Genes From Pigs Only, Not Humans or Birds." "Wired Science," April 28, 2009. Published by WIRED.com.
- CNN.com, article by Elizabeth Landau. "Swine flu origins mysterious in ‘genetic arms race’." Last updated May 6, 2009, accessed May 14, 2009.
- Christopher W. Olsen. "The emergence of novel swine influenza viruses in North America." Virus Research 10 May 2002;85(2):199-210.
- Nathan Seppa. "Swine Flu Genetics Suggest a Vaccine Is Possible." Science News, May 1, 2009.