Avian Influenza A H7N9 Hemagglutinin Antibody

Influenza A virus is a major public health threat, killing more than 30,000 people per year in the USA (1). Novel influenza virus strains caused by genetic drift and viral recombination emerge periodically to which humans have little or no immunity, resulting in devastating pandemics. Influenza A can exist in a variety of animals; however it is in birds that all subtypes can be found (2). These subtypes are classified based on the combination of the virus coat glycoproteins hemagglutinin (HA) and neuraminidase (NA) subtypes. H7N9 bird flu is the newest atypical influenza virus infection that has just been reported since early 2013. The emergence of this new strain occurred in China and has become the present focus for possible worldwide pandemic (3).