Influenza virus is a common human pathogen that has caused serious respiratory illness and death over the past century It has the potential to cause widespread pandemics A pandemic occurs when a new type of influenza strain appears Swine
influenza has come It has affected a large number the swine flu (H1N1) virus the United States and elsewhere have put the health authorities Swine fl u virus to cause infection Swine
flu virus generally circulates throughout the year the Centers Control and Prevention (CDC) have received reports