Evolution and dynamics of the pandemic H1N1 influenza hemagglutinin protein from 2009 to 2017

AbstractThe emergence of swine-origin pandemic H1N1 (pH1N1) in 2009 invigorated extensive surveillance programs worldwide which have resulted in the deposition of large numbers of H1N1 sequences to Genbank. In the present study, we report on global evolution and dynamics of the pandemic H1N1 influenza Hemagglutinin (HA) protein in viruses isolated from three different continents (North America, Europe and Asia) during the period between April 2009 until April 2017. Close to 2000 HA full protein sequences were downloaded from the Influenza Research Database of the NCBI and analyzed using DNAStar to run an alignment, the web-based NetNglyc to predict N-Glycosylation sites and finally, the BEAST software package to calculate evolution and substitution rates. Our analysis improves upon other published papers in that we report on frequencies, dynamics and impact of HA mutations in pH1N1 viruses isolated from three continents during the past decade, as well as the evolution rate and site-specific selection pressures. Sequence based analysis demonstrated substantial changes in the HA protein over the last decade. Results showed that theHA gene is under negative selection (P value; HA= -2.253). The evolution rates varied among the three continents ranging from 2.36 × 10−3 in Europe to 3.18 × 10−3 in Asia. Mutations were detected at higher frequency and faster rate at the antigenic sites surrounding the receptor-binding domain (RBD), in particular, in the Sa and Sb sites. Mutati...
Source: Archives of Virology - Category: Virology Source Type: research