Virus circulates in human, bird and animal, causing seasonal epidemic and occasional pandemic outbreaks. In the past century, the world has faced five pandemic respiratory diseases caused by different subtypes of influenza virus and pigs serve as major reservoirs of these influenza viruses. The 1918 H1N1 (Spanish flu) which originated in Spanish killed around 50 million people worldwide, 1957 H2N2 (Asian flu) that originated in China killed around 4 million people worldwide, the 1968 H3N2 (Hong Kong flu) killed 1 million people worldwide, the 2005 H5N1 (Bird flu) which affected more birds and humans and 2009 H1N1 (Swine flu) which caused 18,000 human deaths and encircled over 100 countries infect human, pigs and birds. Another pandemic has born from family of coronavirus, two regional epidemics are severe acute respiratory syndrome (SARS) and middle east respiratory syndrome (MERS) in2001 to 2003 and 2012 to 2015 ,respectively. In2003, SARS had killed 774 people, while MERS killed 858 people between 2012 and 2015.