tailieunhanh - Báo cáo y học: "Mutations at positions 186 and 194 in the HA gene of the 2009 H1N1 pandemic influenza virus improve replication in cell culture and eggs"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Mutations at positions 186 and 194 in the HA gene of the 2009 H1N1 pandemic influenza virus improve replication in cell culture and eggs | Suphaphiphat et al. Virology Journal 2010 7 157 http content 7 1 157 VIROLOGY JOURNAL SHORT REPORT Open Access Mutations at positions 186 and 194 in the HA gene of the 2009 H1N1 pandemic influenza virus improve replication in cell culture and eggs Pirada Suphaphiphat 1 Michael Franti1 Armin Hekele1 Anders Lilja1 Terika Spencer1 Ethan Settembre1 Gene Palmer1 Stefania Crotta2 Annunziata BTuccino1 Bjoern Keiner1 Heidi Trusheim1 Kara Balabanis1 Melissa Sackal1 Mithra Rothfeder1 Christian W Mandl1 Philip R Dormitzer1 and Peter WMason 1 Abstract Obtaining suitable seed viruses for influenza vaccines poses a challenge for public health authorities and manufacturers. We used reverse genetics to generate vaccine seed-compatible viruses from the 2009 pandemic swineorigin influenza virus. Comparison of viruses recovered with variations in residues 186 and 194 based on the H3 numbering system of the viral hemagglutinin showed that these viruses differed with respect to their ability to grow in eggs and cultured cells. Thus we have demonstrated that molecular cloning of members of a quasispecies can help in selection of seed viruses for vaccine manufacture. Findings In the spring of 2009 a novel type A influenza virus of swine origin S-OIV bearing an H1 hemagglutinin HA and an N1 neuraminidase NA was isolated from acutely ill humans 1 . Unlike some novel influenza strains such as recent H5N1 strains of avian origin S-OIV is not highly pathogenic 2 . However it is readily transmissible and has spread globally in a new pandemic. Young people and those with medical conditions such as asthma are at particularly high risk for morbidity and mortality from S-OIV 3 . The public health response to the emergence of S-OIV has been swift with the rapid manufacture testing and distribution of monovalent pandemic vaccines and inclusion of the pandemic strain in the trivalent vaccine composition recommended for use in the 2010 southern hemisphere seasonal immunization .