The Influenza Virus And Pandemics

The influenza virus was infecting its hosts long before the discovery of viruses in the late 1800’s. The longevity of the virus can be attributed to its ability to quickly mutate its genome, which consists of only eight negative-sense RNA segments. These small mutations allow the virus to rapidly evolve. In fact, approximately every twenty to thirty years the virus evolves into a “super virus” capable of causing significant pandemics (Webster, 2014). The influenza A virus is the envelope virus responsible for infecting hundreds of thousands of humans each year, however strains of influenza A virus have avian lineage. An intermediate host, such as swine, is usually used by the avian virus to evolve with a mammalian virus through genetic reassortment …show more content…
A strain of the virus with pandemic initiating capability can arise at any time. Knowledge of the influenza A virus’s genome could reduce the destruction caused by the development of such a virus. Scientist are currently working to understand what mutations occur in the genome of the virus, where the changes occur, and how they affect the functionality of the virus. Observing the protein expression of virion can track how mutations occur through generations of the virus. Previously it was believed that viruses could easily produce large quantities of virions containing a full set of functioning proteins. However, recent studies have shown that most influenza A virion contain only one or two proteins and are incapable of producing infection offspring. The study of protein expression in the influenza virus also reveals that the multiplicity of infection is positively correlated to the successful transfer of all surface proteins to virions (Brooke et al. 2013). The lack of full protein expression was found to be a common characteristic among RNA virus, providing insight not only to mutations affecting proteins of the influenza virus, but all RNA viruses. Rockman et al. went beyond observing the presence of proteins in the influenza virus, and began analyzing specific changes of amino acids within the HA and NA proteins. Their studies revealed that a majority of changes to proteins occur at the globular head, which corresponds to the make-up of antigenic sites. Identifying these sites as the point of mutation in proteins reveals how viruses are often able to evade the response of its host’s immune system. The small changes in the receptor site make the virus unrecognizable to any pre-existing antibodies. Links between genes in the evolution of the virus are also being used to predict the virus’s next evolutionary step.