Human Swine Influenza: a pandemic threat

Influenza (Flu) pandemics are caused by new influenza viruses that have recently adapted to humans. The influenza virus, known to be circulating as a pathogen in the human population since at least the 16th century is notable for its unique ability to cause recurrent epidemics and global pandemics. Genetic re–assortments in the influenza virus cause fast and unpredictable antigenic changes in important immune targets leading to recurrent epidemics of febrile respiratory disease every 1 to 3 years, consistently necessitated the development of new vaccines. The current Influenza vaccine available is unlikely to provide protection against Influenza A H1N1 virus. There is no specific vaccine available for H1N1 strain. Each century has seen some pandemics rapidly progressing to all parts of the world due to emergence of a novel virus to which the overall population holds no immunity.