Hemagglutinin of the Influenza Virus
As the influenza virus continues to mutate so too does the hemagglutinin gene. As the genes of the influenza virus continue to change, they tend to cause novel antigenic strains -- this is the reason we have seen so many epidemics in our history.
As scientists use 560 viral rNA sequences, the structure and the rate at which it mutates. As the HA sequences of the HA and NA proteins of the influenza virus aggregate into clusters, the virus takes on new characteristics -- which is when new vaccines must be made to prevent the onset of a new virus.
By studying the hemagglutinin gene, we can also learn the potential of a new virus being a threat to a species. They also tell us what the relationship is between the cluster of HA and NA proteins are.