1、Antigenic Shift v. Drift in Avian and Mammalian Sino-Influenza Type A Viruses.,By Charles Hauser, St. Edwards University Mark Maloney, Spelman College Young Kim, Northland College Michael P. Saclolo, St. Edwards University,Issues,Role of viral hemagglutinin diversity in pathology Creation of new vir
2、al strains Antigenic shift versus drift,Influenza type A,Subtypes designated by Hemagglutinin (H) and Neuraminidase (N) expression,Subtypes,H and N are on surface H and N are components of flu vaccines Subtypes A (H1N1) and A (H3N2) are common human viruses,Vaccines must match subtype and specific s
3、train,New flu viruses evade immunity: Antigenic Shift vs. Antigenic Drift,Antigenic Shift,New subtypes match different H and N genes Avian and human viruses mix and match in swine,Antigenic Drift,Small differences in sequence within a subtype define strains “alleles” or different versions of same H genes,BIRD FLU,“Bird flu” is unusual Some strains of avian subtypes (H5N1, H9N2, H7N7) can directly infect humans,Module Components,Chinese Avian and Mammalian Influenza Hemagglutinin Sequences ClustalW Alignment Dendogram Analysis,H5N1,H9N2,H3N2,H1N1,
