Molecular Characterization of Pandemic Influenza A Virus A(H1N1)pdm09 in Southern Palestine

Abstract

A pandemic influenza has been announced in 2009 caused by a novel influenza A virus A(H1N1)pdm09 which spreads globally and has a high transmission rate among human by the WHO. Waterfowl is the source of all influenza A subtypes; A(H1N1)pdm09 occurred due to antigenic shift when the avian and the swine influenza A subtypes combine in the swine cells and result in genetic reassortment that leads to an unprecedented combination of haemagglutinin and neuraminidase subtypes creating a virus which is able to transmit efficiently to which human has a naive immunity. The human viruses bind to the epithelial cells located at the upper respiratory tract at their sialyoligosaccharides by SA α2,6Gal whereas avian viruses attach to SA α2,3Gal. The swine respiratory cells contain both receptors proposing that the swine serves as a “mixing vessel” by providing a place for the reassortment to take place. Hemagglutinin (HA) and neuraminidase (NA) proteins are expressed at the surface of the virion and are responsible for the viral identification, replication and transmission processes. Besides, they evolved rapidly to escape the immune system via the genetic drift rendering the vaccines of low efficacy. A(H1N1)pdm09 is associated with high mortality rates and led to the death of millions worldwide.