Are there any similarities between the H1N1 Novel Influenza Virus and earlier pandemic viruses?
Flu viruses are classified by two proteins on their surface, called H for hemagglutinin and N for neuraminidase. The H1N1 Novel Influenza Virus found in Mexico and the 1918 Spanish Flu viruses are of the H1N1 subtype. Both viruses appear to have originated in animals. Researchers believe the Spanish Flu spread to people from birds. The two viruses are not identical, and there are still many genetic differences between them that researchers are studying.
